ioiete rere tte te pietereigetele® jasliofer er sanere ret exer Fee y : neers sat ere ere duierete tiene ingested tenet Subeese ENP IP TY Soe AUTEN FF naeterws ee oko sah ed ae (gow wees erry ele eeswrere hint eI es deel Ea OPE PP Ty so eptadedie Petite ae nae Pei hye verre wyatt she hilt adielinaaege te oat whe Am tage a teat oY pete ep reyes ste’ cm Aalenete tage ate hater anal ey ATS OTH ee ee i a : ee iar al at weet SOR yw ee Tw egy pate RH hele 1G pa tele Wl a GENT TRAE FOS” Vee Ldeatindain died “eine eieate nat ets Oe ee ee ? ers a Kall eeenes ore atin aia an tints wnt wie oe Se epmermpere hohe eat pnd panther arerivent sees : oe OT LOGOS Pere . 4 fi . sa eens 4 rosie or "vr aoirsrerare oc eaetoheta — e a ’ : , te ee eee . - ee inter arr . rere x . OE Ee NE TE MEN PE HITE 4 Samah mean send “ srs 2 “ ee ee ete ‘ we saga aw aw ere R Coy a . ie first < seahe fagromee * vere oi + oe 4 i bls ee OS ESOS Jy~ Sin rw ae ie aoe " . sa ee we eine tet ei tehetw! ad SSSR pe ae Se awa na Nin yt ate al rere 18 we salad SRA? . iy ¢ ab dvd . ; : 2 0 ¥ PPP POO WN ee hr we abner Pe VTE ada tod acaba deena weyers wipe et we re ed repre et a ee ee or ver eee ith tnd dite dete VON Rev vee et ot = Pree rere Pee Te et ee Oe , Wesddivy, AAR he tat ww . lal \ adh elias ay ue al vit Adda ee ‘. Adee AA ad Ave, iid dea ae sot ANA AH "Xe re r= “Jue Wore, cd ‘e \ ra w we wi eity’- «Nye LEEte Al | Ma a wr wh tan Ly AMAIA ¢, } ‘ww we Th ‘Ss ‘we on | ve P) oar AM . were shy ve, 8004 wn bax tay Vl wy wv- ’ E 2 ee) | | j ‘ . » Nemeway sy WATT Wer borer AWte AAA > am oy Woy 4 LEE <* *. SE Ota ee pt Mg mA Sire : he ah r ‘y*, TALE ARR “a Wy se heonen’s, teed qe i} a i| & oc NES A WH aparbet nd hae Pate PTL | | Ll a pre LIT rina Wig ros ae, fgg we ‘VEROTUERANY wi ve " : eB , | hai) » ! Aa KITE RE Ay idan" Peat ie ee a-vvur ws yyy remy ey t404 sae es qiy.. ie ae Ai IH | AC AAAS . itil tenn nA LAA | reser batts pee Fa ite Lory 3 Hear y - aaa steel ye bla FID RA S + aed “oe LN 7 | \y Wri @ PA Wa te fe syn ANw* “ Mgtieenn eer! UT held! iil Vessel iygaivlll 45, nm Vi. ow be! |e Aa di NM att oo, a + Pye ~) ty ney UIE St neennattlen, Wy TEER ep RIA Ma qr 72. _ e A KS ‘ v. ” vuylte a A et. WAS RAARA DT suas? HEAL wae! Q NA sy Wey Md CENT a SELON auapong - p| a ~ 4 "sce e ¥ Sj gre » pre | vee aA Y Rabid ee } WON nn. ur wail vt 1 ‘Segue \ a MEE hapa ie Mitel || ha wets ghe aes Me 1g) ‘* vw | oe ern a hin HTi stp pee LLLP IM TM4 one ee RELI f aca! st . as i Pid ee Soe Pratt atts re eeasveul” Ld | ose Toe R IIT ee yi, ree "Vey 'SECG, se id eee yidere dquse WM a4, aed va belinda | j Ss *. th f ~@ Nalin, Veg Dues see heen ha. OO Wer An bitelala | bev eyyt bap 1) ride A ie ‘an. ¥ heheh cugdthar ee, ’ ~ sue A ‘Z + ig = A | ow a at atl, a sci ve Ha - eile 4 we “4 at \ 4 iw? Boy AA pt Md anne (finn “ gt 4 ave cvsperh et ne hetty prvagthaee a pas dl Us vs : bE ee tT aabea a ae A | 7) ; poribTetthey i) eee | oe ae od wd GU Were. 9 a a, | A a tt Pr at of Oe ban et Deleded op Chey MAAR LP eee gieet es mn hgh TOI i LS badd fs AP aera yy ; ne MAT Y 25 oy ‘ pey athe v a MAL ad Joao MI 3, wes 7h eae oo es ueny t fee UVCvuay “* ) AAPA SAD JF NST pestis tt tf 10) C00N) eng ysl mee had tc AMAA CI” vv WwWuvwe” “sey ae! dou gwrrthey ON a : fy Avy TD PEEPS ne cou PPT PL | y f , yws. =w~Y s ie . a % j Pe SE 3 “eae {ARTICLE 2.-EXTRACTED FROM THE REPORT OF THE U.S. COMMISSIONER = OF FISH AND FISHERIES FOR 1892. Pages 65 to 304 and I to V. Plates 1 to 47.] ; oa a tg a = ? Et WYXOSPORIDEA, OR PSOROSPERMS. OF ISIS AND THE ab eh) Vd a EPIDEMICS PRODUCED BY THEM. BY Rosh. GU Ris ¥5 M-- Ds, Assistant, U. S. Fish Commission. oe [Date of publication, December 28, 1894.] pete nana ee -- Ae \omonlan instip | . f> “ ic 4 7™ ¥ ; | A ay ; ! | ations Mouser®; WASHINGTON: _ ae GOVERNMENT PRINTING OFFICE. anes 1894. re [ARTICLE 2._-EXTRACTED FROM THE REPORT OF THE U.S. COMMISSIONER OF FISH AND FISHERIES FOR 1892. Pages 65 to 304 and I to V. Plates 1 to 47.] MIXUSPORIDLA, OR PSOROSPERIS OF FISHES, AND THE EPIDEMICS PRODUCED BY THEM. BY R. R. GURLEY, M. D., Assistant, U. S. Fish Commission. [Date of publication, December 28, 1894.] —— pels an Nie ¢ te 247440 WASHINGTON: GOVERNMENT PRINTING OFFICE. 1894. 2.—THE MYXOSPORIDIA, OR PSOROSPERMS OF FISHES, AND THE EPIDEMICS PRODUCED BY THEM, By RK. EK. GuRLEY, M. D., Assistant, U. S. Fish Commission. TABLE OF CONTENTS. Page. Page. GN aENeNIRILTOT a cise ca 12 (a\sen= im latoidlsi ais wisn = 65 | Description of genera and species—Cont’d. General description of the Myxosporidia. .. 71 OrdorGryptocystese. 3-4 -saceeteeseeeernis 190 I. Nomenclature and definition ------ 71 Hamilys GLU Geld ee). 22.5 a saleeetas ee 190 JUL, Likos a nel Gye s = BBS Bee Spee ooeceese 73 Genus Gluces.-2--- 4. saseeenaae te 191 General description of structure. - 73 Genus Pleistophora................ 194 Detailed description of individ- Genus Thelohania ..--...-.....-... 195 TL REPU CUAEGS! qs siete sai See oe 75 | Ordo Phenocystes) > -sees2-08- 45a 205 Le Zoolomicall position... ..-....---- 93 | amily Myxobolidie s-2-5 .ase-e so see 206 GV oO TS DE CO UGLON ston a/=ieyetaresais ais = laiainricls 100 Gents) Myx oboluse so. eae. os eee 206 Vie LORS IN CANON. assem Description based upon Thélohan’s (Compt. Rend. Acad. Sci. Paris, 1890, CxI, p. 693). For the process in the Cryptocystes, see p. 201, 3 Journ. de Microgr., 1884, vill, p. 474, Fc 92 6 82 REPORT OF THE COMMISSIONER OF FISH AND FISHERIES. Development of the sporoblasts into the spore-—As noted by Biitschli and Balbiani! in the 2-capsuled forms (Myzxobolus), each sporoblast divides into 3 unequal uninucleated masses, 2 small and 1 large, des- tined to form respectively the 2 capsules” and the sporoplasm. a. Development of the capsules.—Very soon there is produced in each of the two smaller masses, ordinarily in the neighborhood of the nucleus (see above) a small, rounded, clear vacuole, distinguishable from the surrounding protoplasm by the absence from all points of its wall, of granulation, Next a small protoplasmic button forms at some point of the wall and advances progressively into the vacuole, crowding its con- tents back against the sides, so that after a time it becomes a pyriform body surrounded by a clear layer (the vacuolic contents) and connected with the protoplasm by a pedicle. Little by little the pedicle becomes strangulated, the pyriform body thus finally becoming free. During this time it has acquired a membrane, and a filament is produced within it, evidently at the expense of its protoplasm, although Thélohan was unable to follow all the stages of the process. Around the capsule thus formed one finds the nucleus,’ and débris of the protoplasmi& globule which has given birth to the capsule. The nucleus remains most frequently attached to the capsule, but sometimes it becomes separated and is found engulfed in the sporoplasm. During develop- ment the capsules have no fixed direction, orientation taking place later. b. Development of the sporoplasm.—The third mass becomes the sporo- plasm. Very early 2 nuclei, generally near together, are seen. They persist to maturity. Thélohan was unable to determine whether these exist primitively in the sporoblasts (which would then contain 4 nuclei instead of 3, as Biitschli supposes) or whether they result from division. c. Development of the finished spore.—The spores, until now rounded or oblong, very soon assume their definite and characteristic shape and acquire an envelope. The tail is folded against one side of the spore, becoming straight only after the rupture of the pansporoblast mem- brane, which latter persists a rather long time. Biitschli for MW. miilleri; Balbiani for M. eilipsoides (see pp. 218, 223). 2 Not rarely, especially in Myxobolus ellipsoides, 3 to 8 capsules are found. The constant association with each of a nucleus shows that their formation takes place in the usual manner. In this case the [pan]sporoblast without doubt incloses an -abnormal number of nuclei. Sometimes it even seems probable that a single spore is ‘formed instead of 2 (Thélohan). [It would be exceedingly interesting to ascertain whether in these cases the number of rejected nuclei is correspondingly less. Unfortunately, at present nothing is known on this point. | ' 8Thélohan here remarks that in a preceding work (Compt. Rend. Acad. Sci. Paris, 1889, crx, pp. 920-1, and Annal. de Microgr., 1890, 11, p. 210) he considered these nuclei as belonging to the sporoplasm and attributed to them a different origin, an errer which a study of the development has rectified, THE MYXOSPORIDIA, OR PSOROSPERMS OF FISHES. 83 THE SPORE. The myxosporidian spore always consists of at least 3 structures, viz: a shell, one or more capsules with filament, and the single mass of sporoplasm. In My«obolus (p. 207) there is also sometimes present a fourth structure—the tail. Pfeiffer! regards the myxosporidian spore as the equivalent of the individual falciform germs (sporozoites) of the Coccidia. THE SHELL. This was noticed by even the earliest observers, who commented upon its most prominent features, viz: its extreme transparency and resist- ance to the strongest chemical reagents. Creplin? was the first to observe the separation of the valves after prolonged immersion in water. It is extremely probable that the shell substance is the same throughout the whole group, as we find the constant shell characters to be the micro-chemical ones, variation appearing to be rather struct- ural than chemical. This substance is thin, very transparent, insolu- ble in the strongest acids and alkalies in the cold, certainly in some, and probably in most species destroyed by (soluble in?) concentrated sulphuric acid at its boiling temperature;® usually with little affinity for staining reagents. The shell possesses a minute pore (or pores) for the exit of the spiral filaments. Two types of shell are (provisionally at least) to be distinguished. These are the bivalve shell, and a type in which no bivalve structure has been detected. The first type comprises 2 subtypes, viz: (a) plane of junction of valves coincident with the longitudinal plane; characteristic of Myxo- bolus; and (b) plane of junction of the valves perpendicular to the longitudinal plane; characteristic of the Cystodiscide and the Chloro- myxide. The second type is found in the Glugeide and in Myxidium lieber- kiihnii. Tail.—Confined within and described under the genus Myxobolus (p. 207). CAPSULES AND FILAMENTS. MORPHOLOGY. Capsule.—Always pyriform, consisting of a thick, elastic, brillianc, ordinarily opaque wall encompassing a central cavity; wall drawn out ' Die Protozoen als Krankheitserreger, 1891, 2 ed., p.8. 2 Wiegmann’s Archiv. f. Naturgesch., 1842, 1, p. 63. 3 Balbiani asserts (Journ. de Microgr., 1883, vil, p. 202) that boiling sulphuric acid does not affect the shell. This Biitschli (Ztschr. f. wiss. Zool., 1881, Xxxxv, p. 634) denies, stating that strong heating with sulphuric acid destroys entirely the shell substance. My own experience with several species tallies exactly with that of Biitschli. 84 REPORT OF THE COMMISSIONER OF FISH AND FISHERIES. anteriorly into a duct which pierces the shell near its anterior extrem- ity, affording exit for the filament. Wall usually taking (sometimes retaining, sometimes yielding up upon washing out) stains, especially the nuclear. Thélohan’ considers the substance composing the capsu- lar wall identical with that forming the shell, as both stain in the same way with safranin. From this view I must dissent, as in my experience not only the optical character, but also all the prominent staining re- actions, differ. In particular the capsules are wniformly opaque, the filaments never being visible through them, even in glycerin, while the shell is transparent in the highest possible degree. Further, in Myzxobolus macrurus (other species were not tried) bismarck brown and fuchsin each stain the capsule without even tinting the shell. Two reagents render the capsular wall transparent, thus permitting the filament to be seen coiled in situ. The first is iodine water (solu- tion with potassium iodide). This reagent also causes extrusion of the filaments, sometimes even in alcoholic specimens (pp. 85, 120). The second is strong ammonia water. I have never seen it produce extru- sion of the filament. Biitschhi? and Balbiani® have observed that when the filament is extruded there is (‘as in the thread cells proper”, Biitschli) a very marked diminution in the volume of the capsule, from which Biitschli infers that such extrusion is produced by the pressure of the stretched elastic capsular wall. This may be the cause of filament-extrusion, but might it not equally well be interpreted as the result of such extrusion or, more properly, as a co-result with the latter of a general increase of intrasporal pres- sure? However this may be, it seems very probable that the filament- extrusion which takes place under the influence of such energetic dehy- drants as sulphuric acid, glycerin, etc., is merely a physical effect, the result of the intense intrasporal endosmotic pressure. Thus in several species (among others, Myxobolus transovalis) sulphurie acid produces a pronounced swelling of the spore, extrusion (even in alco- holie specimens) of the filaments, and finally the expulsion of the cap- sules bodily, under an evidently great pressure. It can not, however, be denied that the action of iodine water is not thus explicable. Filament.—Exceedingly tenuous, attached at its proximal extremity to the capsular wall, free at its distal extremity; usually coiled into a spiral; in this condition entirely inclosed within the capsule cavity. Capable of uncoiling and of extrusion (via the capsular duct) as a semi- uncoiled or a fully uncoiled (nearly or quite straight) thread whose length may be many times that of the spore. That the semiuncoiled condition is merely an intermediate stage between the fully coiled and the fully uncoiled condition, and is not a specific character, is shown 1Annal, de Microgr., 1890, m1, p. 207. 2Ztschr. f. wiss. Zool., 1881, xxxv, p. 636. 3 Journ. de Microgr., 1883, v1, p. 204. THE MYXOSPORIDIA, OR PSOROSPERMS OF FISHES. 85 by the occurrence of both in the same species under the influence of sulphuric acid. The other reagents which tend to produce filament- extrusion are caustic alkalies, hydrochloric and nitric acids, ether, glycerin, boiling water, mechanical pressure (e. g., the rolling of a mass of spores in an insufficiency of fluid, under the cover-glass), etc. As noted by Biitschli,! the extrusion in the latter case is apt to be more or less abnormal. Concerning filament-extrusion in preserved material, Thélohan? says: After the action of alcohol upon the spores the filament remains in the capsule and it becomes impossible to make it go out. While not usual, extrusion does sometimes occur with alcoholic speci- mens, a certain (rather small) proportion of the spores emitting their filaments under the action both of sulphuric acid and of iodine water, In my experience the filaments appear usually not to have much affin- ity for stains; the capsule where stained, always shows a markedly lighter center. Kolesnikoff, however, found them to stain in Myxobolus kolesnikovt. HOMOLOGY AND FUNCTION, The capsules were first observed by Miiller (see p. 241), who consid- ered them the embryos. In 1852 Leuckart * regarded these structures as fat globules. He says: Also, they [the spores] contain s¢me plain granules of a fatty quality, which are distinguished through their constant location in one or both poles. In 1863 Balbiani‘ discovered the filament and its capability of extru- sion. Regarding the spore as an adult cryptogam, he assigned to the filament the role of an antherozoid. In 1875 Schneider® remarked that— As regards a resemblance between the falciform corpuscles and the polar organs of the psorosperms of fishes, it is impossible for me to find it. * * * The falciform corpuscles are not such sacks occupied by a slender filament rolled into a spiral. Commenting upon Balbiani’s views, Leuckart says:° The signification of the elements is unknown, but it may be safely admitted that _ Balbiani’s view, which sees therein an antherozoid, is without foundation. Perhaps it is to be regarded as an attachment apparatus. He further remarks that a comparison of the capsules with the falci- form corpuscles is excluded by Lieberkiihn’s and Balbiani’s observations of the exit and ameeboid movement of the sporoplasm. 1Ztschr. f. wiss. Zool., 1881, xxxv, p. 635; see Myxobolus miilleri, p. 219. ?Annal. de Microgr., 1890, 11, p. 207. 3 Archiv. f. physiol. Heilkde, x1, pp. 434-5. *Compt. Rend. Acad. Sci. Paris, Lvu, p. 159. This discovery has since been con- firmed by numerous observers. 5 Archiv. de Zool. Exper., Paris, 1v, pp. 548-9. Ihave not seen a distinctly asserted comparison between the capsules and the falciform corpuscles to which this could refer, but such a comparison is implied by Leuckart’s parallelism of Myxidium (?) sp. 102 (Archiv. f. physiol. Heilkde, 1852, x1, fig. 21 b) with the'spore from the testicle of Lumbricus. ®Die Parasiten des Menschen, 1879, 2 ed., p. 247. >. 86 REPORT OF THE COMMISSIONER OF FISH AND FISHERIES. Upon the same subject Prof. Biitschli! remarks that: Balbiani’s view that they [the filaments] represent male fertilizing elements com- parable to the antherozoids of the cryptogams, may be entirely rejected, as, apart from the general improbability of this view (which, moreover, is not further supported by actual observations), there are, at present known, no vegetable spermatozoon-like organisms whose structure permits of comparison with these nematocystoid polar corpuscles, Prof. Biitschli? regards the capsule as comparable to the nematocysts of the Celenterates. This view is, he says, supported by its develop- ment, the filament being originally in the extruded condition and only Subsequently becoming retracted and coiled. Further Biitschli re- marks that: One might suspect that the capsular filaments serve for the attachment of the spores to other fishes or to the food of the same. Taking the two together, I interpret Prof. Biitschli’s meaning to be that morphologically they are nematocysts, but that here they function differently. Replying to the preceding criticisms of his theory, Balbiani* says: This last observer [Biitschli] compares with reason these filaments to the urticat- ing organs or trichocysts of the Celenterates. But, knowing the signification of urticating organs, I admit that I do not well understand in what way these organs can serve psorosperms which are completely immovable and do not nourish them- selves, for one knows that the trichocysts have for their object only the paralysis of prey in order to render its capture more easy. And further, among other repetitions of his theory, he says: We have, in effect, here, all the phenomena of sexual union (rapprochement) ; first, the embrace (rapprochement) of two individuals; then the presence of a female element, the sarcodic globule, becoming free at that moment; and, finally, filaments which I have compared to antherozoids. In a word, the process recalls involun- tarily to the observer a cryptogamic sexual generation. But these interpretations, although emitted with reserve, have drawn upon me on the part of Leuckart and Biitschliasevere criticism. These authors prefer to compare them to urticant organs. One can respond by asking them what would here be the physiological signification of urticant organs, which are offensive or defensive weapons. What would be, in these organisms, their réle and utility? At all events the phenomena in question deserve to be studied anew. I was then as much, if not more, in the right to consider them as antherozoids, than Leuckart and Biitschli to make of them urticant organs. We had, I believe, equal reasons, the German observer and I, to sustain our interpretation. Curiously enough Balbiani shows no indication of abandoning his antherozoid theory (on the contrary it is further elaborated by the designation of the sporoplasmas the “‘ female element”), notwithstanding 1 Ztschr. f. wiss. Zool., 1881, xxxv, p. 638; Bronn’s Thier-Reich, 1882, 1, p. 603. 2 Bronn’s Thier-Reich, 1882, 1, pp. 599, 600. 3 Biitschli’s own observations for the Myxosporidia. The same very probable for Hydra (Jickeli, Morphol. Jabrb., vii, p. 373). Without assigning any reason, Lutz doubts Biitschli’s observation (Centralbl. f. Bakt. u. Parasitenkde, 1889, v, p. 87). + Journ. de Microgr., 1883, vil, pp. 204, 277, 278. ~ ( THE MYXOSPORIDIA, OR PSOROSPERMS OF FISHES. 87 the fact that at the same time he practically abandons' his view of the adult nature of the “ psorosperm.” Kunstler and Pitres? think that the capsules “appear to be true nematocysts.” Ludwig? accepts the Leuckart-Biitschli attachment theory, regard. ing the filaments as probably organs of attachment. He says that though little is known as to the conditions under which filament-extru- sion naturally occurs, spores kept long in water extrude their filaments, and adds: Probably the filaments serve for the attachment of the spores, which have reached the water through the opened tumors of the fish, to any living or dead substances whatever. . Thélohan* comments upon Prof. Biitschli’s view as follows: Biitschli, after having severely criticised that idea [Balbiani’s antherozoid theory], compares them to urticant organs. At the outset, as Balbianiobserves, one can not see what could here be the réle and the utility of urticating organs. Further, the filament of the polar capsules resembles but little those of the true nematocysts 5 after their exit they present most often a sinuous aspect, sometimes neatly spiral, which is far from recalling the appearance of the urticant filaments which shoot out abruptly from their capsules and present themselves under the form of rigid bayonets. Mingazzini> takes a totally different view from other authors and -one which it is impossible to reconcile with the present evidence. In the following passage, besides other errors, the (capsular) filaments are confounded with certain shell-processes (ribbonettes) described by Balbi- ani in Myxobolus eilipsoides, and further Biitschli’s view (given above) of the function of the filament is curiously distorted: Many observers have noted (in treating the myxosporidian spore with various reagents) the exit from the polar bodies of a very long filament, which normally is coiled within the polar body. As to the signification of this filament various opin- ions have been emitted. Balbiani thinks that it can serve as the organ of dispersal of the spore, functioning at the maturity of the latter in a similar manner to the elaters of the Elaterium spore. Biitschli expresses the opinion that they can have the signifi- cation of urticant filaments. But Balbiani has further observed that in the mature spore these filaments are unwound and stand each around either the membrane of its own spore or around that of a neighboring spore, and supposes that in the last case the fila- ments have the signification of copulating organs. Again, however, Biitschli, not entirely satisfied with his first interpretation, has thought that the function of urti- cant capsules for a spore which has a membrane resistant to acids and alkalies, is a kind of luxury, and that the filaments could serve to attach the spore to other fishes or to feed it [italics my own for errors]. From an analysis of the opinions it appears that none of them is entirely satis- factory, while, in my opinion, from what I have seen of the gregarinoid forms, it may be assumed that the polar bodies are nothing else than the embryos of the Myzxosporidia, homologous with the falciform bodies of the gregarine and coccidian spores, on which view the filament of the polar body would be nothing else than the tail of the gregarinoid form which remains inclosed in the polar body while 1 Journ. de Microgr., 1883, vi1, pp. 198, 201, 276. 2 Journ. de Microgr., 1884, vin, p. 474. 3 Jahresber. d. rhein. Fisch.-Vereins Bonn, 1888, p. 33. 4 Annal. de Microgr., 1890, 11, pp. 207-208. 5 Boll. Soc. Nat. Napoli, 1890, tv, p. 163. 6 See above (p. 86). 88 REPORT OF THE COMMISSIONER OF FISH AND FISHERIES. the mass of internal protoplasm would represent the residual nucleus (nucleo di reliquat) of the spore. The homology is demonstrated with all the greater proba- bility, inasmuch as, a8 in the gregarine and coccidian spores, the number of the falciform bodies is constant with the species, so also in the Myxosporidia the number of the polar bodies is constant in the different species, and the residual nucleus would serve to feed them within the spore and perhaps to determine their exit at maturity. There would thus be explained what was seen by Balbiani, viz, the exit of the polar bodies at maturity without having recurrence to the forced interpreta- tion of fecundation (which would not be constant) or to the unsatisfactory inter- pretations of Biitschli. Wecan thus see in the spore of the Myzxosporidia all the parts that are encountered in that of the typical Sporozoa (the Gregarines and Coc- cidia), and in this way more easily discover the zoologic link which connects these groups with the Myxosporidia. Perugia! accepts the Leuckart-Biitschli theory that the filaments are organs of fixation. Hecompares them to the long filaments of the eggs of parasitic Trematodes. This writer has, however, followed Mingazzini’s error, and confounded the ribbonettes (described by Bal- bianiin Myxobolus ellipsoides, p. 223) with the capsular filaments.” It is necessary to direct special attention to this error or we shall soon find an elaborate table of structural synonymy a necessity. He says: Balbiani compares them to organs of dissemination such as the elaters of the Equiseti. Having afterward observed that sometimes this filament is coiled around another spore he saw in them an organ of copulation. Lhélohan asserts that he has observed that many spores are destitute of such a filament and evinces an inclination to regard the filamentous organs as accidental productions(!) [Italics my own for errors. ] Pfeiffer® regards the filaments as organs of mevement or attachment, saying: Probably this organ is no thread-cell, but serves for progression or attachment. He? asserts that these structures also occur with the falciform germs of Miescher’s tubes, and says that the spores of the Myzxosporidia and Sarcosporidia are, according to his representation, not at all so widely different from one another. Further, inthe description of fig. v, he says: A well-developed falciform corpuscle; to the right the large colorable nucleus; to the left a noncolorable indefinite body with a beak-like process at the left pole (thread-cell?). Thus, in spite of the unqualified statement in the text, there appears to be no certainty as to the nature of the structure in question. Turn- ing to the figure, all that can be said is that it is entirely too indefinite to sustain the weight of the assertion of its capsular nature, against which view the verdict of ‘not proven” must be placed. 1 Boll. Scientif., Pavia, 1890, x11, p. 137. 2?Thélohan has recently pointed out Perugia’s error (Bull. Soc. philomat. Paris, 1892, Iv, p. 167). 3 Die Protozoen als Krankheitserreger, 1 ed., 1890, p. 47; 2 ed., 1891, pp. 17, 132. 4Ibid.,1 ed., pp. 47 (and footnote), 99, plate, fig. v; 2 ed., p.183. It will be noted that Pfeiffer says nothing of, nor do his figures show, any extruded filaments. Nothing short of this could be accepted to prove the capsular nature of the body iz buestion. See also pl. 7, fig. 5. THE MYXOSPORIDIA, OR PSOROSPERMS OF FISHES. 89 Remarks.—Balbiani, Thélohan, and Mingazzini appear to assume, as the basis for their criticism of Prof. Biitschli’s view, that a structure morphologically a nematocyst must necessarily be urticant in function, in other words that the terms nematocyst and urticant organ are synonymous. This assumption is, to say the least, very dubious. Concerning the homologies of the organs in question it is impossible to see how, as suggested by Mingazzini, they are to be brought into comparison with the falciform bodies of the gregarine and coccidian spores, inasmuch as (as noted by Schneider; see p. 85) the falciform bodies are not in any respects structurally similar to the myxospori- dian capsules, and further it would seem (as implied in Leuckart’s view above given) that the homology should lie between the protoplasmic structure in the one spore, and the protoplasmic structure in the other, whereas Mingazzini’s parallel is between the protoplasm in the one and a structure which shows no evidence of such composition in the other, being apparently destitute of such characteristic protoplasmic struct- ures aS nuclei, vacuole, ete. I can not, however, feel much greater confidence in their homology with the celenterate nematocyst. I can only interpret homology to mean such correspondence in development and structure as would (upon the evolution theory) imply descent from a common ancestor, and con- versely no homology seems possible except in cases where (upon the same theory) one would be willing to admit such common origin. In the present case, while the myxosporidian capsule shows a marked histologic resemblance to the ccelenterate nematocyst, it presents one very important difference, viz, that it appears and functions at an en- tirely different period of the life-history, i. e., it characterizes the spore and disappears before the adult stage is reached. Add to this the point cited by M. Thélohan (p. 87), and their (probable) utter uselessness to the myxosporidian spore as offensive or defensive weapons, and the parallelis by no means close enough to justify their assimilation to the nematocysts. The fact that the myxosporidian filament agrees (how closely ?) with that of Hydra in having the filament first extruded and only subsequently retracted-coiled, does not seem sufficient to prove the morphological equivalence of the structures, as it might be possible that this mode of formation is the only one capable of producing the necessary elastic tension. Further,’ “nematocysts” are known in some mollusks. All these facts render it very probable that these ‘““nematocysts” have been independently evolved in the different groups. It may, however, well be a question to what extent of detail all of these “nematocysts” correspond. As regards the function of the capsules and filaments, the only intel- ligible suggestion that has yet been made appears to be the view of Leuckart and Biitschli, which sees in them an apparatus for attach- ment. I can see no basis in the facts for Balbiani’s antherozoid theory, 1Lankester, E. Ray, 1878, Encycl. Britan., 9 ed., v1, p. 108. 90 REPORT OF THE COMMISSIONER OF FISH AND FISHERIES. and no evidence in favor of Mingazzini’s supposition that the capsules represent the embryos, the filaments functioning as flagelle.! On the contrary everything that we know about the Myxosporidia favors the view that the embryo is not the capsule but the sporoplasm, the presence in it of nuclei, of a vacuole, and of amoeboid movements being quite conclusive. The most probable supposition in relation to the capsules is that they are accessory and temporary structures whose function is to secure attachment and perhaps a certain amount of motion, for the fulfillment of both of which objects they seem very well adapted. And it may be noted in passing that nematocystoid bodies are known which function for attachment, as well as those which function for stinging, ete.” Before discussing the mode of action of the filaments, a few words may advantageously be devoted to the relative functions of the spore and myxosporidium stages. (1) Dispersal is absolutely necessary to the species: This dispersal can take place only by the actual separation of myxosporidian individuals from one host and their migration to another, unless we adopt one of two very improbable suppositions, viz, either that they attach them- selves to the eggs of the host and await their development or that they develop in an intermediate host which feeds upon the fish.? (2) The spore is the means by which such dispersal is effected:+ Thus Lieberkiihn® saw some cysts ‘‘lost” and others opened, their contents escaping into the water. Also Ludwig and Railliet (p. 228) have observed the rupture of cysts in situ with escape of their contents. Thélohan® has seen the same occur with Glugea anomala; and in Myx- obolus ellipsoides he saw cysts shell out entire and burst.’ 1 Mingazzini’s description given above implies very strongly this idea as to the function of the filaments, nevertheless he does not distinctly so state. Compare here Lieberkiihn’s statement (Bull. Acad. Roy. Belg., 1854, xx, pt. 2, p. 21) that the capsules, when extruded with the sporoplasm from the spore, show not the slightest trace of movement. ; 2Jn the body epithelium of the Ctenophora we find peculiar adhesive cells with uneven and sticky surfaces. Their bases are prolonged into spirally coiled con- tractile filaments.—(Arnold Lang’s Text Book of Comparative Anatomy, London, 1891, pt. 1, p. 82.) 3The latter mode of change of host, though improbable, is not inconceivable. Still, everything seems to point toward the view that the whole life cycle from the attached spore in one generation to the liberated spore in the next, takes place in the same host. 4The only place where this view is distinctly stated is the following (Mlle. Leclereq, 1890, Bull. Soc. Belg. de Microsc., xvi, p. 101): “On account of the presence of organs compared to nematocysts, but which seem rather elaters, one can believe that the spore is the disseminating form of the para- site, and that it can lead for some time a free life in the water.” [Italics my own for errors.] Here we again see the unfortunate results of the dual signification 0: the term ‘‘ filament.” 5 Miiller’s Archiv., 1854, p. 356. 6 Compt. Rend. hebdom. Soc. Biol. Paris, 1892, 1v, pp. 82-4. 7Annal. de Microgr., 1890, u, pp. 203-4. The observation was upon a spore habi- tant on the tench (Myxobolus ellipsoides?). THE MYXOSPORIDIA, OR PSOROSPERMS OF FISHES. ot Finally that, in at least one species, dispersal could hardly take place by the myxosporidium is shown by Biitschli’s observation! that in Myxidium lieberkiihnii that structure dies rapidly when removed from its natural habitat (the urine of the pike) to even “indifferent fluids.” (3) The myxosporidium, on the other hand, is the post-embryonic, comparatively stationary, growth-reproduction stage: There is little reason to suppose that there is ever any migration from one host to another during this stage. The evidence all points to the conclusion that after (and probably soon after) its attachment to the host, the valves of the spore separate, freeing the sporoplasm, which thencefor- ward is known as the myxosporidium. Thus Lieberkiihn, Balbiani, Pfeiffer, and Perugia have all seen the sporoplasm leave the spore and exhibit amoeboid movements. Now, if this view as to their relative functions in the life-cycle be correct, the capsular filaments may conceivably serve in several ways. First, they may serve as a flagelliform swimming apparatus, a view that [ think quite improbable, dispersal being more probably effected by currents, ete. Second, they may (and this is probably their most important function) serve for attachment.’ Further, if it be conceded that, after attachment, motion is necessary to the spore, the filaments might easily subserve such function either by a maximum extrusion, fixation of the tip, and a subsequent coiling- retraction (similar to that of the Vorticella stem), the spore in this case progressing “ anterior ” end foremost, or by a minimum extrusion fol- iowed by fixation of the tip and progressive uncoiling-protrusion, the spore in this case being pushed “ posterior” end foremost. In Glugea anomala, which has but one filament, 504 long, motion could hardly be effected in the latter way. But such motion is easily conceivable with the 2-capsuled (Myxrobolus, ete.) spores; and if it were admissible to suppose that the final lodgment preliminary to reproduction is ever effected by the spore and not by the myxosporidium, the latter being liberated and growing in situ (a view which, however, the present evidence tends to negative), this backward motion would be the best possible for inserting the spore under a scale, especially for those species provided with a tail, which latter structure would form an efficient guide to such insertion. IL incline, however, to the view that the func- tion of the filament is attachment, and that the motion necessary for the attainment of a place for reproduction-encystment is effected by the liberated myxosporidium. 1 Ztschr. f. wiss. Zool., 1881, xxxv, p. 639. 2 Perfectly consonant with this view is the observation of Biitschli (Ztschr. tf. wiss. Zool., 1881, XxXv, p. 635) that the filaments are extruded in spores which are pre- served a long time in water. For we thus see the floating spores ready for instant attachment to any object with which they may come into contact. A possible cause for such extrusion might perhaps be found in osmotic pressrre (preponderant endos- mosis from the surrounding water) from within. At any rate, it is difficult for me to attribute the rupture of the shelled-out cyst observed by M. Thélohan (see p. 221) . to any other cause. 92 REPORT OF THE COMMISSIONER OF FISH AND FISHERIES. SPOROPLASM This was noted (but apparently regarded as a third capsule) by Miil- ler,' and it appears inseveral of his figures. Subsequently Lieberkiihn? observed its exit from the spore and its amceboid movements. He also notes its visibility within the spore.* These observations have been confirmed by Balbiani* and later by others (see pp. 263, 287). The sporoplasm is extremely transparent, more or less granular, and contains nuclei (1 or more), sometimes a vacuole, and, at any rate in the genus Myxobolus, a variable number of brightly refringent granules. Nuclei.—These were firstdemonstrated by Thélohan.’ Their number is variable in the same spore, according to the stage of development. In Myzxobolus ellipsoides, Thélohan demonstrated their origin by contin- uous division from a primitive single one. He further says® that all species studied by him (with the possible exception of the Glugea species, in which the small size of the spore prevented accurate determination) have shown 2 nuclei. This accords with my own observations. Granules (‘‘refringent globules,” etc.).—These have been noticed in several Myxobolus species. They are described under that genus (see p. 209). Vacuole.—This structure is of two types: (1) The noniodine-staining (aniodinophile) vacuole. This is known only in, and forms a marked characteristic of, the Cryptocystes. It is situated in the large extremity of the ovoid or pyriform spores and is unaffected by iodine. This structure was first observed, but not at that time recognized as a vacuole, by Thélohan.?. Subsequently he recognized its true nature.® (2) The iodine-staining (iodinophile) vacuole. This is known only in, and forms a marked characteristic of, the Myxobolide. Itis stained by iodine dark brown against a light yellow-brown ground. This reaction is best obtained with a dilute solution (aqueous, with potassium iodide). Further details are given under Myxobolus (p. 208). 1 Miiller’s Archiv., 1841, p. 484, pl. 16, fig.3 7, k; ef. fig. 5. 2Miiller’s Archiv., 1854, pp. 355-4, pl. 14, figs. 7, 8. 3 Bull. Acad. Roy. Belg., 1854, xxi, pt. 2, p. 21. 4Compt. Rend. Acad. Sci. Paris, 1863, Lvm, p. 160. 5’ Compt. Rend. Acad. Sci. Paris, 1889, crx, pp. 920-21. For Perugia’s confirmation, see Myxobolus? merlucit (p. 242). For Biitschli’s ‘‘nucleus”, see p. 219. 6 Compt. Rend. Acad. Sci. Paris, 1892, cxv, p. 1092. 7Annal. de Microgr., 1890, 11, p. 211, pl. 1, fig. 17a, b. 8 Relatiye to the homology of the vacuole, Thélohan says: ‘Is there any connection between the central vesicle and the rest of segmentation of the other Sporozoa? * sn5u0[qo | xX Pee “SN.SUOTGO v}Z9ONS MOZATILIGE {i]t SAPS OORGOGI. ra tsisc0)) | faa ven lsat) 6) C6050] 2S5e 6) og) Boel vail ba Sconeoe| seraa\s). aco) eed. **""- gesuo00 snpeydesoydo'T #6 [voce wsipsep | x |X fooccfecce free feecfece} x foes efeeete ee feecpcee fee cco eee fee @necee|Pood|sc “77> Bnbe snseqynepeydop pI eg pers SIPISV | X ee am O Di iar ariel a | pe ame = le a | ea eiaeane ee | Ceo aaa a vorurysed sryeAsn(y Ng becesbaraie mantel OD sat ax alee) ener Nae ae poco passa = c= = (sis Basu $6 [ctr op:--:| x TAGS Gaye QoelIocic “s77""* BivroumlIvUL Opedio f, 1 ee optttt] KX |X froeefec eee fe erie ee] 9c fee ere ecto ee[ece |e ee fee cee eee ef ee ee op:- sereeres==-On9d10} Opedio J, ‘HCG EP Rae Wsrpsgy | x LOPPUIG [[BH)"— "=| s GOT ie gcse re qaoourds | Xx --sjoup opiq ---*|-- tt re Sel % Bae O Pista ea lit Be Peete eel ts Br Asaaieerosces anne S222 QNess-|-22-/== “7775*>-> puenbs euyendg SeOpioes lex BRE) UPORGT ICRC ADOC OG ~* SNULOJSOUVOU SHINS Ga tntoks Yolo etetet lalate op:---| x 22880 @yNPOAS|OOOD | socomoneer “--*"BTNOTUvO SNULGIOpAS TONpos ss SG 400 ag cele ce PS a acco tle sei Se ODS PSA S SRS STS Sets Si aes Baer | eee eee ete SHUT e eau Teas Tt OES ASLO LaLIRS AG ONS) SG eal RO GR =o SAR OOI AIRE om cS Palo 9/50 > apo Bac 2 oociciCiDOODS Co aoe leaded si ee ody ar So POSS RCSA EGOS UcC.0¢ic| cicgcnone Seer aa od #6 |rcocce eee msrpsop | x | xX freee free e| cfc efe ce] xe [eee desde cde e fee feee eee eee fee eee 0) Rie BOS) EE OOO B ORO OS sc Corn CSOD SC cHinGroCc se booniironcL > --snjeysSnur sne[TBy 1g [rrseeee wsotnaeayds | x | Xx Jro--[ee otic) ee] og fener efeee|ece]e ee [eee |eee eee ee ee |e Gy Pee3 Pood BeGho Sono pp Sr scocaalspocmuatid||SoocnS octco|lsccnc *-"sno[es snurq.09pe+y FG [occete te mstpser | x Hea) 9) OI AIL Heeler clly eee ase “*-s"""-SBTgyuvoR snpeubd HSTpAgy R PRET IL tq} ibe Ss kar | :S00Slq 86 |----- s++-+-sXxodrp | X Fe SGDe ie || POSE sIoSooSD San BERS IRS FESS Ste na glace med Maga near acm gece soeeeeses’ BUVPHITA XI1}.10 T, :eoosuy Sh | Weare at ruvefeyuoo | x eee ee >“ SI[I}VIANE snovjsy ra jegmenel I ge Pee ects Boa isi io SSR OE OCC 2B CC1IROR cc OOS SROOTS) ee A OCO SCR CCH IS oC tS DCSCE SOC RSE OSORG Gn DGS COSI). Sve ee I GGONOGoe SLIBS [TA WOS URL) && ROA Hoya AIO) Se [COPE RES Clemo mab ae Sol SOE 8 5 O0) SCC col FSO CSDE De “""""* SUBLIBA SOJOUOMI B[V I Ie op 7] X freer cjeeee|e oe ]e ee fees fee eee ee fee [eee fee edocs eee sor eces"" SnqQeIIOS UOT Te |rccccee W10U80}00 | X [ooo jeter e foot feeefecede estes ce} gg [eee [ee ede ee |ooe teres ee “*77"* SLIQsOdqood WOM@[e :BQ0vISNID oF [--- 70°77 *- quoout ds | x [reee|---|---- ecsiellletare Se a a ee ees ees Senn eee eeeoer *--> goprosoqoad ste Ny AQLABO [BI + SoULI0 A 94." — «Saptozoxiq | X | X |r-77|---- SEG EGGS tio S250) 2 acl oo val cia}syo.y (2) ull OOGOr DOGO PocGiSGGn OE ROCCO aS OS gal PESO SOS Do asic “oe ses-Bsonuny BauOLo[ Vy . :wozs [og 2 nl Ee] © Z| alala BI | @ td | ie siais & Si/4i eo) c & | = a E th ob 2 Bs 3 3 a E 2 AiR lal wile lSisio|] w | ale 5 g Sxee S| o 2 Ee a a De oO S D be 8 ole|s ° eal us| | o Ta0.4 sy B =] eA ic) 2 “logs Bis /elicls!] ole] 5/8] @ J = Sy» | = ore) ae = ie 3 FIS|SIBIEISieiel le] & |Feeck | 2] Se F oF * . te} Sey co eet ani > se Bi eee ~ . ° setoedg By Bilsieiaia| & =| § ¢ es YAS 2 = — 1 480 Ee Pe cen rc cane sree 4 g Bose | m ° 5 s a : "15 . oa B Baor ® ? a 3 : 2 ge a 3 uaony apes *snuoy *yuag 1 SS ee a a a eS ee Sa ee ee ee ee a ‘sjsoy fq fj) v01bojooz uoyngr.ysyy REPORT OF THE COMMISSIONER OF FISH AND FISHERIES. 102 ‘ON sotoodg | T1o[[ NUL scsstnileierns , Turpaelap [teeteeeeeese: Opies vetteereeeess press teceveeeereres Opies: qaoour ‘ds ToT [NUL qa9our "ds OTH eIAny pains *=*> qugouL ‘ds qaoout ‘ds Sees +--+. Turpaefap sessecces- argu ds Fisisiivs ---- goproposo jor or eeees SNINIOBUL H ; q.1edut “ds SIULLOJIAO soees’ To] [UL minoleisieies: --gzgout “ds [Fecitincrier-pTOoUL “As "ee" sngvpnsdvorun | x x x xX XX X° KX KXKXXKXX x XX xx x x *soloodg ulMtpriodsox Apr “UMN I prxd PL | ‘exAuore@qds UMOUY ISVS *snosrpoysfg "ex AULO}V.1ID POUL “vIoydo sol *snpoqox ATT ‘umn xAUIO.LOTYD “BIURI “snuot) ye frtteeseee: “AAT -Avo Apo [[eAd [Ro “Tys0} UL !AQTABO -yIvdy “AYE -AvO APO | ee ee eg et ‘lop -pelq [pes saisieis SOS e OSE Scop ayala)=(s “BVIpOUBIG -opnosd risigisisizisinig 25% *-*-| ‘9rozado bere ee oo) ope] ee i iis ees xrnpoavaq ‘Bupo avg > erypoueaq | *£IBA0 fou pry *AIBAO ‘OUplLy ‘aoe, ds “sno qus “£poq Seatatele ala etal otetl| Rate eemtate eas eae ener veg seccceeesens|sccceesccersscoosses acy “shut -jeqgqdoiyyf19 snostoney “snuyeyyydor -qjAdo 40 Snytyna snostone'T imeimin OUISRISIIS suosroneyT BE OES tars agate od eqsianses | si - Resse Sesshisa ee SRO sgocecosiegec| as “----snjeqdeo snosione'y Sosa serene |eceee sete ee eree ee ees OT tec eteseeeeeeeeee=-Qc7 weer eee een es) seen ece ee eeeeeeeeees soy cicie siewiieisye sn{gui snostone'T sTalelaisajets siet=i>} eielezs sijeyqonu suqyeusog Ay °d = sacenincesese= OTGOs OL0D peewee wee Oe od -7*""--snqueq suqieg cieinirininjincinic.njeinicicie’s |= **"="Snorjolia ooqe'yT sine aeccncene|--ec=--nIASRIUO SHISSGIED ‘ponuyuopj—seostg “q100UT snUe+) *SNOoUvT[IISTL pue Te) *soTnqny In pue “JOPPRTG LV | ‘sgonp e[Iq ‘saappryq Arvo ArvUL -lan . qt “ABO [BLIP MBAIg, *suvS10 PI[OG “90BF -INS [Bus] XIT “‘sOpOSN IT ‘80H -4v08 *ponutyu0j—s)soy fig fhjpwohojooz woyngi.gsig 103 THE MYXOSPORIDIA, OR PSOROSPERMS OF FISHES. oes" -snanZzigos “7** purpdoedo “yo [UP P SPORES Lntefa oq ectolls 09 |*- 77777777 STereyds (OARS 9g ODE OC RERE 0) zee ZR lp =n TODUT Cs.) 18 |-°7°° "> “LAO MTUSOTOY 89 | Te ypoosz JT, |PP2OGOGOS =) dda} 019 Ba) vale === TOOTS) BORE EOS SC SlIvoUuly] -7* snanypAduo014s el srpenbdout (29 ly Se = SLIVOUTT | ile a ee eee SIUULOJLAO Jife) | CERES CACSRONS TSELEL) 22--- Opree: sets teeeees opie Satelers gael’ op’ So c----- = queoun-ds QP |°7 7-7" >> SNZwISOOIq, GF 77777 soprosdiyya e@ occtttee sysfoAyouaq Gg |r ro o> srumzogiard ey |---°7*-=>- qaoour ‘ds Cit)_|| Sse SI[VAOSMBIy pete) TOGO OOD er gagour ‘ds XxX XXKXXKX XX XX fee OCI Cert hake) (2) “DLodso.1ayds « aUT}SoyUL ‘top ‘op see ssseee-! erg [RSs weet )ee ete e eee ejeseseeeees|-- > prog topes “opr *sotpode eg a LY tet 0 |e ee ee Seta fe etenelolade eve) Steir Peller L TG RETO) *solpore "R[LOUR] | [UO UB Ig) See -wW9o UL X |wrpourvaq |--- JOATy |" rote eee al ee Emilee CORT tas ‘uoojds ap “oer ouBlg -- uoods phage aie ey BIOG) BS SISOS OG ears GO Herc alaye fiat *LOUpLy ay, AT[ey bay FO ee GRR ISSA EU AMO temas boom BORD OOD OOO] UO OAN rN Gg ||P eric JA RY Ea VHT (C0 [Sis meee fae ape orn ge -uenbs ~~ *91q.2t0 x “OUSSTy 9AT}O0N “109 avpNo “SU [vty -1} 8 d04Uy “OUSST] AvTNO “STLULLOPILL "$008 “0d PC II OREO CEH oe al on ETO UMTS REED Meta OPED AOSTA ISAO OI OGY GT Coren Ye wer tteeseeceeseeseee gee rtteeeeeseeeeeees Og "Tra" "* BIOT SNUODIIN 5 sores oo SEOUL SRUNTOULY Pots tetere seeeeeeee og wan} -vlosuy vuroys sdopesout srdo1j0 Ny *777> SOplO[UpMNy SHULXOl Fitness tht eres tee so terre eeeee pec e ee eee e eee renee OC ‘ON soroads | 104 REPORT OF THE COMMISSIONER OF FISH AND FISHERIES. vente *---"-1m01]d9.20 as qaoour “ds Sens sicimms qaoour “ds \----snorutradsorosd eee rin oS qas0ut ‘ds Sees ies qaoour “ds 0 5) Toe aaa cle ase ODGHRS Oe Tongans vpeMOUB eis sia SUTpouL 7" * STAQIQ > ,SuBse]o Pan seirsca SuLpout See es STAI IS poi BRNO € ‘ds pote 2 ae 3 SnDInNUWOUL ce eae aie ae IWO}UTT Sag TEAR 10q oT] § 77 snoLtutedsoaosd | | | ‘sor00dg OS ac. oe aa op:**- Coats enias op-77: “unrpriodsox Ayr “4 anes Sais ek ec | Kadrnoi ca ial lee POPUL | ‘eroydoystora | ‘vasnyy | “snpoqoxAyy | ‘snostpoyssg | “BIURl "exAu0yv1a¢ | ‘exXuroraydg | ‘yaoour snaey | “snoouv[[oostyy ‘unx "==" *"""SNS1LOULOUIT “**7"> TIOTOBUITTYO *- SNS20 ULUUT vyeTnotpusaddy eee : Ironpom (a) oye er 2. SECT TEQ one eeeOL OLLOLG, woes" TONG BAITOUL UI. B LOLOL Sip snanydrp eee sees opette Weeeeeeeeees pete ---qr00ur ‘ds SOD sr veers s = TUIVAINOUT se ss°°"-SiTond}sep Poeicicee ele asta B[BULOWe Sse --<-7990UL “ds sreesseee--grpord Ay To] [War SOGOU 0 HUT Ty Ezy OL x ROS XN V4 4 WKN) OK LX xX PS APSE PR ok URS wy ee eel celle ee Ax “STavpno “situ pur BsoouuUL [vurjse}Ur “far x LOppRyTq [[vs}"- ~~ “Topped ‘send -ny [euor | see opeeee|: ----op-7--|> ope: sees oprrse fer : IOppLyq [[e5|* "Toppryq Areutan at ae op -avo Apo |----*"°7-""7|---- wore eeseseesss , OTIPOI0T() ,, Purrydoy “-"" SuqeT[ooo suyvasyssg ss 57""5* SNSOULSI}Me] Oy Aree PRISONS | aires eian nate f PBITPORAyEg “--">-sniioqyvostd sniy doy pec =s= “SNTOUpLOU SNIONIOPL ee SLLYBTMOVUL SNUQ Settee tees esse betes ogy tress -ocy SESE ORGS lil cna auth ehe C0) sn Peseleiiersicls rin === G(r ---0q eee Cee Eeny ya Jalciete cleiateisi t-te Rag OTE OT SOS SOSSOSE|SODO AGS Cou ial fs) a hedo2) (a7 IB FEISS 0 56 [oS ISIS OG | ecco IOS 4 a (oad suey el 2 ICOOIOOH HAG Ef haere NeKoyy (240) “snoou : SOOO CROA|OPORC IES), Tiina Le ats}| POI OO OC SEARO CRS mc omen eg Hee ot) ee eee ie --- LIVAO "IVT Taqy107 a1 see "=-STTTABIANE SNIGOX seeeees=---oTd1008 §N}J0D -+++--gdooml sniqe[fmerg s 106 REPORT OF THE COMMISSIONER OF FISH AND FISHERIES. ORGANAL DISTRIBUTION. ORGANAL DISTRIBUTION OF THE GENERA AND SPECIES. Perugia! remarks that there is a marked difference in seat between the Myxosporidia of marine and those of fresh-water fishes. In marine fishes they occur principally in the gall bladder, while in fresh-water fishes their organal range is much wider. The finding of cysts on the branchie of the marine genus Mugil (see p. 213) rather corroborates than contradicts this view, inasmuch as these fishes ascend rivers for a long distance, and those which yielded the myxosporidian cysts also yielded a Trematode of a genus peculiar to fresh-water fishes, viz, Tetra- onchus vanbenedenti Par. & Per. The organal distribution of the Myxosporidia is very extended. The following points are of special interest, and comprise the principal anomalies of distribution not covered by the tables below. Nervous system.—No species have ever been reported. Testicle-—No species have ever been reported, a fact which,” consid- ering their frequency in the ovary, is very surprising (cf. the presence of “ Myxosporidium” bryozoides on the spermatoblasts of Alcyonella Jungosa; see p. 187). Superficial tract—General similarity of conditions, histologic struc- ture, and fauna justify the fusion of the general surface, skin, scales, the branchiz, the eye, and the air bladder into one tract. ‘The charac- teristics of this tract are principally the predominance of connective tissue, and (?) a relatively larger supply of oxygen (see p. 224). Air bladder: Only two species are known from this seat. Both of these occur in Cyprinide, in which the bladder communicates freely with the intestine, and hence presumably contains oxygen. This fact, the histologic similarity, and the fauna suggest very strongly the pro- priety of including the air bladder in the external tract. The species are Gen. incert. sp. 15 and Myzxobolus ellipsoides. Intestinal canal.—They would appear to be very rarehere. I am not aware that any species has ever been reported from the lumen, the nearest approach to it being one (Myxidium? sp. 102) from the bile- ducts. And yet such a species as the last must almost certainly find its way into the intestine; probably, however, as separated, single Spores, very difficult to find. In addition, Myxobolus ellipsoides and M. sp. 51 (the latter from the wall), and finally Gen. incert. sp. 17 (which, however, may or may not be myxosporidian) occur on, or in the intestine? 1Boll. Scientif., Pavia, 1890, x11, p. 139. °As remarked by Thélohan (Annal. de Microgr., 1890, 11, p. 197). 3The fact that M. ellipsoides and M. sp. 51 are, of all the Myxosporidia, the species having the widest organal distribution, should not be lost sight of in considering their presence in unusual seats, THE MYXOSPORIDIA, OR PSOROSPERMS OF FISHES. 107 Liver (exclusive of gall bladder and ducts). But two species are known here, and these are the two which have the widest organal range, viz: Myxobolus ellipsoides and Myxobolus sp. 51. Kidney.—In only a few instances has any distinction been made between the stroma of the kidney and the tubules. It seems, however, not improbable that, as regards organal distribution, a distinction should be made, and the tubules be regarded as a part of the hollow fluid-filled urinary tract, the stroma forming a solid connective tissue seat. The following occur here: “Kidney”: MM. piriformis, M. brachycystis, M. milleri, Myxobolus sp. 51, M. ? sp. 65, M. diplurus. Renal tubules: Myxobolus brevis, M. medius, Chloromyxum (S.) elegans, C. (S.) ohlmachert. Spleen.—This organ has furnished: Myxobolus piriformis, M. brachy- cystis, M. Ellipsoides, M. sp. 51. Ovary.—From this are known: Myxobolus miilleri, M. sp. 51, M. brevis (2 hosts), M. medius (2 hosts), M. ef. creplini, Chloromyxum (S.) elegans (2 hosts), C. sp. 91. Excretory tract.—For purposes of organal distribution, the gall and urinary bladders should be considered together, as they present prac- tically identical environmental conditions, both being internal (which means a uniform temperature) and both being fluid-filled. To these cavities may perhaps be added, as exhibiting similar conditions, the bile-ducts and the renal tubules. If, now, we consider this tract as a whole, we find that its rich and peculiar fauna stands in strong contrast to the species inhabiting the remaining organs. For we find absolutely confined to it the following: The Chloromyxide except only Chloromyxum dujardini, the Cystodiscide, except the insecticolous Cystodiscus ?? diploxys, and the Mywxidiide. Besides these, only the following species occur in this tract: (a) Inthe gall bladder: Genus incert. sp. 9, “Myxosporidium” congri,} Myxobolus? merlucii. (6) In the renal tubules: Myxobolus brevis, Myxobolus medius. In the following table all the species—47 in number—whose generic references are fairly certain and whose seats are known, are compared as regards their organal distribution. The unit adopted is the oceur- rence of 1 myxosporidian species in 1 organ of 1 host. The number of such “ occurrences ” is shown for each species by the Roman, and for each genus by the Arabic numerals. 1Spore unknown (genus? See pp. 110,182). ?Generic reference, in the almost entire absence of a description, by no means certain. 108 REPORT OF THE COMMISSIONER OF FISH AND FISHERIES. Organal distribution. Superficial tract. Excretory tract. 5 5 i=] ~ series ye a oe BES Le 8 s a 2 ee eck ae H sz Babe SS eee Clk Sng |e as 20 = ici eee ee Genera and species. Se eas Oe (Sites = Se eS sees Pp SAS o' ga k| & Od Kole oS % 7 aa RES| o ai 3 © Ele S |B Sele oc'o/S | so] Ke Spal ta th ee te 4 g(*gecnbos/ Si S12°> (elle |FlSlel es : SlpandiSuse/sle2/5 |8|/Pla jal] s |e 5 2Qigos aake2i 2/8 rs 2 eid =i ee ©) = HFPlSQHe AERA eA = AS ey b = oO a R = —z A | ea) S| PEN TS) fz Sve MN fee; tas; Sy |iees Nn 1 Syl sapcacae Joon [Serd|kocaod eer aes === eer $one\G5n5|b Seq loa) (Cdlntecers 2) es, eel ee se es SI ET S65 ses \eossa> Se er a [eros destruens.. 2. Jj.-ces-ces2 27 Se pe | Rae Soe A BS al ett Pepe ealeeeeleeecias Be) ose) hase eee anomala lees ese chooses 28 2 oe ea eee ee Shoo essere aise peel SSec|eeaaeic SL lst be-sl-— nal Ue lelstaphoras aD Woe rortas ovel| eae cowl + ee Meese Bieta ae ei Ba ase ance hy Plcalis. ~~ 22 aac aes seeeere 29 Dl pametew cela scecer es leacrallseete| aoe ce : a aleedase Se eeleeer|=o--|) Lheliehania: Ei re epee ee eee eS CEE PR eee ee eee | meee el eee Re Bee Gontejeanis---a-seese eee 30 SAT ee ea ceyas,| | Se es Re le ne Aes Seodllsosditoodes Seay Sees teaee Serer OCLOSpOTa =e =e === eee eee 31 UR eee ees hoe ake > apace cleralacte Sooses 2 : Mardiss == oe oe eenee es 32 df ee ecrer eased AAR aac errese eecsace : wanes MACTOCYALISy--asceceeneee 33 — z a -- — : 3 10 TV le st a Dieiera| areal Area. --|----|----| Miyxobolus: Tides Sees | ee dale chee Soles se| ease Saale ated cots Kolesnikovizeessssesedess 81 ’ Mig ee meetoletceee lemeatnes<|asecine pied |secilosecse Salesce|sees| ae Spsineert/---oscee eee 82 Bea | Seen ae I IE |S 3e JE 3 < one Sp: incert)- {4s se seeeeen 51 ee Lee | Se Bsa eae ced yae|sacace oaelaene OblOngUS) = = ss. see eee 54 s Rh se as LES alk Seo Be 2 S865 |lsa5¢00 ae Senlbe ee Jintoni:< sss 2ece cee eee 55 ee 1) wl See eeet Hecclkesse5 SHEA GA SCE ler ‘ as transovalisie-aasessasee 63 Soe TA Ae te > ae Bena oe pee See ae ete a strongylurus .-----....-. 73 re 1 Sees to BE | eet cee 22s mall = ees B eases MONUTUSss te oe eee 74 ars "Ge a fe ae te Ae |e A Se ee ea | aes > A ae MACIOTUS Hse eeeee se ee eee 75 AS 1B) ee oe Oa ee IEE ean alt kN ae aloe 5 ae cilinearis@essscnnee eee 7 se 1 OE | eat Ee MC ee a aie = dGoeallooes oe eae | See aral| renee | wees schizurus. 22 -u =e oeee eee 79 Pod oT 3 CE) Oa) |e ae Se [Sjecelice eel ese Tee ANS Calla [eps OVILORMIS. ace esos ee eeeeee 42 jae at STE Pea? Be te 5 aN IG Ete |B ET | eee lt Ce MULUCLLEcaace ee eer eee 46 B84 Sesecace if Sooper 2-00 | oe Se ae elie ere SO ae all 5 ie atl yes Ap incertm. see seeenes 76 Sele lemie teres. I SSA 0 Il FS Sears | eet ae ele Eee (meen 8 Se Paar TlODOSWScess2.cecseee eee 62 Serle bec If Be eS OL ae Bese llaee ee cieee Pe ea ee ee a ge Spuneertieecss- S22 ceemeae 45 ewes Scere ste iE) Og oA ee ol Me a Sa on| Bee Rene a eee Aa 8 2 ee linearis) - 222 2P hee ae 78 eects UE pee heeee 3 2 BSA Se bes Sead lobed boro bose psorospermicus.......-..| 80 Ee a eee it IGE 3e oF: Bee Semel sewers a Tee eee ellipsoides'secek ance canoer 49 wi beet ese I BALES. Somes il 5 py DiPLONMISh eee eee eee 35 ee Beer eee ciliates A ape eee : Beate Cricreplinibee cepts 69 Be Seep Maen a) ae ye pee brevis xisec es ae eS 70 Be ee aon el eee ie, Bee eee! s 2 ae MEQLUS Von sate = See 71 AeA FES SEAS CRS: POC aI pede vada ee diplurusii 35: See be eecee 83 3} 10 TY) LE a | Gey 4*| 4 |. 2.|-.--|-¢.-|-Dotal’ ““oceurrences ” =- — =——'- = =——| — of vacuolate species. eval Sethe Z Sdollebaacor femel 22 1*| 3) 13] 1 |..-.-| Chloromyxum: ‘ Soa pesos 106 es Ae ae Bena pes ers |e ee (S.) dujardini Bee eek area eat sic a RP PE i ES 2 10E Jer V3 00 ae eee (S.) elegans..... Pelee wan beeeee ios Bey ease ooee coe Roaeee ele Gi Nae (S.) ohlmacheri ee et ell eee een PS | ae | ene ee = Oh See oe |e gel] eee ee INCisumM=s 2222 eee eee ecslaeecouns|senscei|c ose sree Hl awarcvts joas|bece| pesos Pe GES a ellaase leydiguil-. 2.25: S2pceeeeee salseeceReleaenee oe lteme PAN ee eee | eeytr| | ss oie ciel] yak] PM eee ee An vaabiles =! s< — | 1 Spheromyxa Thélohan.....|....|..-. OB Weeenos (Oo eeonoeraae 3Gi[ he rate gate i rates Oe eects Myzxidiwm Biitschli.--...-. OP seal i(oma) ene ll eetettnte eae x Orr |L Soe e. 0] 0 | * From analogy and general similarity of appearance, this genus can hardly be other than bivalve, tC. (S.) ohlmacheri. tImperfect. Shell and capsules symmetrical; sporoplasm unilateral. From this table we may conclude that— 1. Henneguya agrees with Myxobolus in every respect but one, the presence of a tail. (See also p. 206.) 2. Thélohan’s groups, “ Myxidiées” and “ Chloromyxées,” must undergo rearrangement (see table below); for clearly Chloromyxum, Myxosoma, and Spherospora torm a compact group, with which Myxidium has no character of Consequence in common except the absence of a vacuole. 1 Balbiani, 1883, Journ. de Microgr., vu, p. 274, tig. 64g. 116 REPORT OF THE COMMISSIONER OF FISH AND FISHERIES. 3. Spherospora and Myxosoma do not differ at all in the characters given (the distinction between these unispecific genera resting solely upon the outline of the spore), and the two taken together present only a single character in contrast to Chloromyxum, viz, the number of the capsules. They may therefore be fused as a subgenus of Chloromyxum. 4. Oeratomyxa agrees sufficiently closely with Chloromyxum to permit its reference to the Chloromyxide. 5, Cystodiscus is certainly entitled to separate family rank. To it may be provisionally approximated Sphwromeya, it having the capsules in two groups and a bivalve shell. (Compare carefully p. 278.) 6. Myxidium must form the type of a separate family, the entirely different position and grouping of the capsules forbidding its reference to the Chloromyxide. The following table shows the relations of Thélohan’s classification to the one now proposed: THELOHAN’S CLASSIFICATION. (Fusiform, lcapsuleat each extremity. Myxidium. | one aiet shell formed of two hollow-coneé valves [ capsules: Myxidians. Spores ? soldered along their bases. Oeratomyxa. No vacu- | Flattened-ovoid, more or less elongate. Myxosoma. ole, 2 or 4 , E capsules. | | Spherical. Spherospora. 4 capsules: Chloromyxans..----- Chloromyxum. 1 iodinophile ¢ Destitute of a tail; capsules 1 or 2. Ifyxobolus. yacuole; 1 or batyxobolans. Spore-shell - < 2 capsules. ( With a tail; capsules 2. Henneguya. PROPOSED CLASSIFICATION. GENUS. FAMILY. CHARACTERS. Myxidium .....--.-+---- Myxidiide.....--- Bilateral but not antero-posterior symmetry; capsules in two groups right and left; no bi- valve shell; no vacuole. Ceratomy2@ ....-------- } Bilateral but not antero-posterior symmetry; | capsules in one group (at the anterior end); a Chloromyxum, et sub- | + Chloromyxide ..- bivalve shell, with the valve-junction plane gen. Spherospora (in- perpendicular to the longitudinal plane; no cluding Myxosoma). | vacuole. Myxobolus.-....-.------ Bilateral but not antero-posterior symmetry; capsules in one group (at the anterior end); a Myxobolide....-- bivalve shell with the valve-junction plane par- | allel to the longitudinal plane; an iodinophile Henneguyd ...-.-------- vacuole. Cystodiscus ...---------- Bilateral and antero-posterior symmetry; cap- sules in two groups, anterior and posterior; a | Oystodiscide..... bivalve shell with the valve-junction plane per- pendicular to the longitudinal plane; condition ? Spheromyxa..----.--- of sporoplasm unknown. - THE MYXOSPORIDIA, OR PSOROSPERMS OF FISHES. ila iy SPECIFIC CHARACTERS. Spore-form: This is a somewhat variable character, e. g., elliptic spores, varying in breadth; nevertheless, considerable dependence may usually be placed upon it. Tail: I have elsewhere (p. 207) indicated my belief that the presence of a tail is a good specific character. The length of the tail relative to that of the body (caudal index) will also prove useful. Ridge index: As the width of the ridge bears a very constant ratio to the whole width of the surface of which the ridge forms a part, this ratio is a good specific character, especially as it often differs markedly in different species. Capsular index: This is a character of great constancy, and hence of much taxonomic value. Nuclei: The presence or absence of the pericornual nuclei has proved constant in several species examined by me (see p. 210). The position of the remaining nuclei is inconstant. VI.— PATHOLOGY. Pfeiffer says! that myxosporidian infection is characterized by the rapid disappearance of the nuclei of the infected cells, the infection of the red blood corpuscles, and the attacking of all the elemental tissues of the host, with the possible exception of those of the nervous system; further, through the early spore formation which is unconnected with any external evidence of maturity. And, further, considering how the blood parasites of mys, Lacerta, birds, and of malarially diseased cattle and men,employ the blood-corpuscle membranes as protective coverings for their naked bodies; also, that the youngest myxosporidia, just out of the spore shell, attack the red blood corpuscles; and, further, that the JMyxrosporidia spare no organ or elemental cells (the nervous system possibly excepted), the destructiveness of this group of para- sites must be recognized to be very great; and, further, that the para- site withdraws directly or indirectly a large quantity of blood from the host, is Shown by the hematoidin crystals found in all myxosporidia, Finally, a cachexia, comparable with the cancerous cachexia of the warm-blooded animals, is produced. By a reference to p. 187 it will be seen that Korotneff observed in the polyzoan, Alcyonella fungosa, substantially the same process that Pfeiffer records in Lucius luctus, viz, an intracellular development dur- ing the earlier myxosporidium stages. Mode of infection —Leydig? remarked that an organism like Gen. incert. sp. 4. could pass with the blood current into the various organs, effect alodgment, become encysted, and give rise to the “ psorosperms.” 1 Die Protozoen als Krankheitserreger, 1890, 1 ed., pp. 48-49; 2 ed., 1891, p. 135. 2Miiller’s Archiv, 1851, p. 229. 118 REPORT OF THE COMMISSIONER OF FISH AND FISHERIES. Lieberkiihn! believed that such ameeboid organisms attach themselves to the skin for the purpose of reproduction. Ludwig? thinks that the greater frequency of occurrence on the gills indicates a greater ease of infection through this channel than via the alimentary canal. Also he says: The lymph channels of the connective tissue appear to represent the principal paths through which the parasite spreads itself further through the body. He, however, fails to give any actual evidence in favor of this view. Pfeiffer * says: The common occurrence of the Myxosporidia in all organs presupposes a distri- bution via the circulation, amode demonstrated by the infection of the red blood corpuscles.‘ Effects—Upon this Balbiani’ has the following: Unlike the Gregarines and the Coccidia, the psorosperms spread themselves through almost all the organs, the deep as well as the superficial, the skin, spleen, kidney, air bladder, and even the heart and ovary. They are also found in the cells of the- urinary tubules, and in the young Graafian follicles, which they transform into a pocket filled with psorosperms. As at the same time they increase with great rapid- ity, it results that animals thus infested present grave diseases and may even die. Certain morbid states of fish ought without doubt to be attributed to the Myxospo- ridia. Such is the case of that Merluche® observed by J. Miiller and which was remarkable for an extraordinary emaciation. I have myself often seen roach, tench, and other fishes reduced by these parasites to a cachectic state characterized by a decoloration of the tissues, destruction of the red blood globules, and augmentation of the white globules; a veritable leucocythemia. It is not, then, surprising that this disease can cause great ravages among fishes, above all in the young, which are most often affected. Nevertheless this cause is not usually noted as among those which destroy fishes. This is easily explained; when the disease reigns attempts are first made to explain it by macroscopic causes and ordinarily it is the worms which are accused. This was the case in the epidemic of the tench in the étangs of Dombes; it was the Ligules which interfered with digestion and the fishes died of inanition. Microscopic causes are not the ones most frequently suspected. I believe that more frequent search would reveal microscopic lesions capable of explaining the mortali- ties of. young fish, particularly those living in marshes and in aquaria. Upon this point M. Thélohan* remarks that these parasites are gen- erally well borne, but that sometimes the tumors may cause death by pressure effects, e. g., he saw a cyst in Gasterosteus aculeatus produce fatal pressure upon the heart. The principal extensive epidemics have been those involving the barbels and the crayfishes (see pp. 197, 231). 1 Miiller’s Archiv., 1854, p. 357 (see also p. 185). 2 Jahresber. d. rhein. Fisch.-Vereins, 1888, pp. 33-4. 3 Die Protozoen als Krankheitserreger, 1890, 1 ed., p. 48. 4¥For the latter see p. 288. * Journ. de Microgr., Paris, 1883, viI, pp. 280-281. 6] have elsewhere noted this error (p. 172). The fish in question is Gadus morrhua and not Merlucius merlucius. 7Annal. de Microgr, 1890, 11, p. 203. THE MYXOSPORIDIA, OR PSOROSPERMS OF FISHES. 1D i VII.—MICROSCOPIC TECHNIQUE. The older observers used no reagents beyond acetie acid, potassium hydrate, etc. Biitschli! was the first to use a staining reagent. He believed that alum carmine stained nuclei in the ectoplasm. The first observer to employ modern technique was Henneguy.? Subse- quently Thélohan* employed similar technique, and Pfeiffer* devotes some space to the technique of protozoan investigation. Finally Hen- neguy and Thélohan® give a few additional remarks upon this subject. The following is a summary of the methods recommended: Fixing and hardening preferably by chromic or osmic acid or both (Perenyi’s or Flemming’s liquids °) or corrosive sublimate solution. Washing out, dehydration, paraffining, sectioning as usual. Affixing to the slide by Mayer’s albumen. Where alcohol-fixed material is the only kind avail- able, much may be gotten out of it in the way of study of the spore. Dissociation (1 per cent osmic acid solution; Ripart and Petit’s liquid) shows certain facts better than the section method. Sections are necessary to determine the seat, and, above all, to follow the different stages of development. Culture in the blood (overhanging drop method) is recommended by Pfeiffer for the study of development. Stains:* For alcoholic specimens, carmine; above all other forms hydrochloric acid alcohol carmine is very reliable. For chrom-osmium (and may be tried on alcoholic) specimens, especially gentian violet, double stain with the violet by eosin. Satranin, by Henneguy’s method,* evinces an electivity valuable in the study of development where we have to do with the most complex phenomena of cellular life under circumstances in which the small size of the elements renders observation extremely difficult. The sections must be decolorized in clove oil for a very long time. Small stellate-grouped masses of crys- tals, which are often precipitated and whose presence is very annoying in the subsequent study of the section, may be easily removed by suc- cessive alternate washings of the latter in chloroform and bergamot oil. Valve separation: Most certainly effected by sulphuric acid (cold, concentrated). Vacuole: Best shown by very dilute iodine water (with potassium iodide). 1 Ztschr. f. wiss. Zool., 1881, XXXvV, p. 632. ?>Mém. publiées Soc. philomat. Paris l’Occas. Centen. Fondation, 1888, p. 165. 3 Annal. de Microgr., 1890, 11, p. 196. ‘Die Protozoen als Krankheitserreger, 1891, 2 ed., pp. 19-24. 5 Annal. de Microgr., 1892, Iv, pp. 620-621. 6 Also Kleinenberg’s liquid (Henneguy, 1888). 7Henneguy (1888) also used picrocarmine. 8 Journ. Anat. et Physiol., Paris, 1891, xxvil, pp. 398-400. 120 REPORT OF THE COMMISSIONER OF FISH AND FISHERIES. Filament extrusion: Most certainly produced in the fresh state by strong sulphurie acid, iodine water, glycerin, nitric, hydrochloric, acetic, formic acids, alkaline hydrates, boiling water, ether, etc., espe- cially the first two. In alcoholic specimens, also, occasional spores extrude their filaments under the action of sulphuric acid or iodine. VIII.—DEFINITIONS. Anterior (and posterior): There can be no question that the longitudi- nal diameter is the antero-posterior axis of the body. The discrimina- tion of anterior from posterior is, however, in the absence of cephalization, impossible. I have followed custom in calling the sharper, capsular end “anterior,” and the opposite rounded end “ posterior.” Capsules: The pyriform, hollow, filament-containing bodies charac- teristic of the myxosporidian spore (twinned. vesicles” of Balbiani; ““nolar capsules” of Biitschli). _‘*Capsule” is preferred to “ vesicle” on account of greater definiteness, and to “polar capsule,” as the situation implied by the latter is not constant. Cornua: The pointed anteriorly projecting extremities of the sporo- plasm. They are infero-, and supero-lateral, and infero-, and supero- median. (See also Surface, superior, p. 122.) Diameter, longitudinal: The line formed by the intersection of the longitudinal and vertical planes. Diameter, transverse: The line formed by the intersection of the transverse and longitudinai planes. Diameter, vertical: The line formed by the intersection of the verti- cal and transverse planes. Ducts: The ducts into which the capsule is drawn out anteriorly and which serve for the exit of the filaments. Ends (of the spore): The median (anterior and posterior) extremities in contradistinetion to the wings. Filaments: The filaments which lie coiled within the capsules. The “capsular filaments,” “spiral filaments,” and “ coiled filaments” of the authors. Notto be confounded with the ribbonettes. Host: In the usual sense; see also Seat. Myxoplasm: The protoplasm of the myxosporidium. *Myxosporidium: The amoeboid adult stage; Mutterblase, Leydig. Pansporoblast: see Sporoblast. Pericystic space: The space apparently empty (presumably fluid- filled) surrounding the capsules. Plane, longitudinal:’ Horizontal and percapsular, passing through both capsules and the sporoplasin, and dividing the spore into a supe- rior and an inferior portion. 'For brevity and clearness these planes are defined as if rectangularly arranged about the center of the Myxobolus spore, the latter being supposed to be viewed ‘‘on the flat.” oe THE MYXOSPORIDIA, OR PSOROSPERMS OF FISHES. 121 Plane, transverse:! Vertical and (usually) post-capsular in position, dividing (roughly) the spore into a capsular (anterior) and a sporo- plasmic (posterior) portion. Plane, vertical: Longitudinal and intereapsular, passing between the capsules and through the ends of the spore and the median cornua of the sporoplasm, and dividing the spore into a right and a left half. Posterior: See Anterior. Protocysts: The two smaller segments of the Myxvobolus sporoblast, which ultimately form the capsules. Protosporoplasm: The larger segment of the Myvobolus sporoblast, which ultimately forms the sporoplasm. Ribbon: The shell processes described by Balbiani in Myxobolus ellip- soides (see pp. 223). ' Ribbonettes: The terminal subdivision of the ribbons, termed “filaments” and confounded with the capsular filaments by some writers (see pp. 87, 88, 263), Ridge: The ridge or “ welt” which extends around the circumference, and marks the line of junction of each valve. Ridge index: The ratio of the width of the ridge to the total width of the surface on which the ridge is situated. Seat: This term invariably denotes the organ or part of the body in which the myxosporidian is located (see Neo Host). Sporoblast (and pansporoblast): This term was first used (in the Myzxosporidia) by Biitschh? for the transparent spherical globule formed by the condensation around one of the nuclei, of a portion of the sur- rounding myxoplasm. The spherical Siopele so formed subsequently segments into two hemispheres (see p. 81), each of which gives rise to a spore. Now, Balbiani,*? and Thélohan,* and Henneguy and Thélohan, ® apply the term sporoblast to the two hemispheres. Further, Pfeiffer uses the term sporoblast as a synonym for the whole sporing myxospori- dium. This latter use of the word should, I think, be unhesitatingly rejected as having no warrant in analogy. By the advice of Dr.C. W. Stiles (who has specially studied the equivalence of this and several other terms‘), [ have followed the lead of Balbiani and Thélohan in restricting the term sporobiast to the segments (the two hemispheres above mentioned) formed by the division of the primitive sphere. For the latter (the sporoblast of Biitschli) the term pansporodlast is here used. 1 Equatorial plane of Lutz, 1889, Centralbl. f. Bakt. u. Parasitenkde, v, p. 86. ?Bronn’s Thier-Reich, 1882, 1, p. 596. He says: ‘Since the spores originate from the plasma globules, we may conveniently term them sporoblasts.” Compare also an exceedingly obscure sentence in Biitschli’s next paragraph. 3 Journ. de Microgr., Paris, 1883, v1, p. 275. 4Compt. Rend. Acad. Sci. Paris, 1890, ext, p. 693. 5 Annal. de Microgyr., Paris, 1892, Iv, p. 634. 6 Die Protozoen als Krankheitserreger, 1890, 1 ed., pp. 32, 34, et al. 7 Notes on Parasites; Journ. Compar. Med. & Veter. Archives, New York, 1892, x1m, pp. 921-324. 122 REPORT OF THE COMMISSIONER OF FISH AND FISHERIES. Sporocyst (rejected): Synonym for spore. Employed by Pfeitter.' Sporoplasm: The ‘posterior mass,” ‘“‘plasmic mass,” etc., of the spore. This term is used as the equivalent of the phrase “ protoplasm of the spore.” Surface, inferior: That upon which the inferior valve (q. v.) and the infero-median cornu are situated (see also next). Surface, superior: That upon which the superior valve (q. v.) and the supero-median cornu are situated. These are, respectively, the equivalent of dorsal and ventral, or of ventral and dorsal. In the absence of hzmal and nervous systems and of an alimentary tract, the proper correlation of these surfaces with the corresponding ones in extra-nyxosporidian organisms seems impos- sible. Jnter se, however, the superior surfaces may be correlated by a greater convexity of the superior valve, but probably most frequently . by the further projection forward of the supero-median cornu, which may (2) even reach the extreme anterior end of the shell cavity. | Valve: Each shell half. Valve, inferior: The less convex valve; see also next. Valve, superior: The more convex valve. The differentiation is prob- ably possible in only a few cases. The supero-median cornu will probably form a better guide to the discrimination of the superior and inferior surfaces. View, longitudinal, transverse, or vertical; view along the line of the corresponding diameter (q. v.). 1 Die Protozoen als Krankheitserreger, 1891, 2 ed., pp. 7, 8. HE MYXOSPORIDIA, OR PSOROSPERMS OF FISHES. 123 IX.—BIBLIOGRAPHY-.! Bibliographic reference No. a. The literature by dates, authority, title, and reference. 1838. GLUGE, G. if Notice sur quelques points d’anatomie pathologique comparée, suivie de quelques observations sur la structure des branchies dans les épinoches; Bull. Acad. Roy. Belg., 1838, v, pp. 771-82, figs. I, 11; reprinted and figures reproduced in Rayer’s Arch. de Méd. comp., 1845, I, pp. 266-7, pl. 9. The next is also substantially a reprint of this. 1841. GLUGE, G. II. Beobachtung zahlreicher Balggeschwiilste als epidemisch Krankhosit bei Fischen; Anatom.-microse. Untersuchungen zur allgem. u. speciell. Pa- thol., Heft 1, pp. 202-204, pl.5. Substantially a reprint of the preceding. MULLER, JOHANNES. III. Ueber eine eigenthiimliche krankhafte parasitische Bildung mit specifisch organisirten Simenkérperchen; Miiller’s Archiv. f. Anat. u. Physiol., 1841, pp. 477-496, pl. 16; abstr. and transl. Brit. For. Med. Rev., 1842, x1, pp. 232-233, and (the same article) Microscop. Journ. for 1842, pp.123-124; French translation, 1843 (see below). IV. Krankhafter Hautausschlag mit specifisch organisirten Koérperchen (Psoro- spermien); Ber. d. preuss. Akad. d. Wissensch. Berlin, 1841, pp. 212-221 (fide Roy. Soc. London Cat. Sci. Papers). Not seen. Vi52 Ueber die Psorospermien; Ber. d. preuss. Akad. d. Wissensch. Berlin, 1841, pp. 246-250 (fide Roy. Soc. London Cat. Sci. Papers). Not seen. 1842. CREPLIN, J. C. L. VI. Beschreibung d. Psorospermien des Kaulbarsches, nebst einigen Bemer- kungen iiber die der Plétze; Wiegmann’s Arch. f. Naturgesch., 1842, Jhe. VIII, I, pp. 61-66; abstr. (French) Rayer’s Arch. de Méd. comp., 1848, 1, pp. 269, 270. 1843. RAYER, P. VII. Singuliére éruption sur un véron (Cyprinus phovinus); Rayer’s Arch. de Méd. comp., I, pp. 58-59, pl. 9. MULLER, J. VIII. Recherches sur une variété remarquable de production parasitique morbide avec des corpuscules séminaux spécifiquement organisés (French trans- lation of his paper of 1841); Rayer’s Arch. de Méd. comp., I, pp. 219-234, THe Ge RAYER, P. IX. Exposé succinct d. principales observations faites sur les maladies et sur les anomalies des poissons; Rayer’s Arch. de Méd. comp., I, pp. 260-270. 1845. DuJARDIN, F. x. Histoire Naturelle des Helminthes, Paris, 1845, pp. 643-645. 1851. LrybIG, FRANZ. xi Einige Bemerkungen ii. Psorospermien u. Gregarinen; Froriep’s Tagsber. ii. d. Fortschr. d. Natur-,u. Heilkde, Weimar, Abth. f. Zool. u. Pal., No. 305 (May, 1851), pp. 73, 74. 1 Pfeiffer, in his bibliography of the Myxosporidia (Ztschr. f. Hygien., 1888, tv, p. 436), erroneously includes with the word ‘‘ Myxosporidia”’ the following: Blanchard, Bull.Soc. Zool. France, 1885, x,p. 291. The citation is an error and Blanchard’sonly paper in the volume (pp. 244276) is sarcosporidian. 2 According to Pfeiffer (Ztschr. f. Hygien., 1888, Iv, p. 436) these 3 articles are the same. They are here given separately on account of the different titles shown by the Royal Society’s Catalogue. 124 REPORT OF THE COMMISSIONER OF FISH AND FISHERIES. Bibliographié reference No. 1851. Lrypie, F.—Continued. XII. Ueber Psorospermien u. Gregarinen; Miiller’s Archiv. f. Anat. u. Physiol., 1851, pp. 221-234, pl. vii; abstr. Quar. Journ. Microsc. Sci., 1853, 1, pp. 206-209. 1852. REMAK. X1iI. Ueber die runde Blutgerinnsel und iiber pigmentkugelhaltige Zellen; Miil- ler’s Archiv. f. Anat. u. Physiol., 1852, pp. 144-149, pl. v. LrEucKART, Prof. RUDOLPH. XIV. Parasitismus und Parasiten; Archiv. f. Physiol. Heilkde, Stuttgart, 1852, XI, pp. 484-436, with plate. 1853. ROBIN, CHARLES. XV. Histoire Naturelle des Végétaux Parasites, Paris, 1853, pp. 291-321, pls. xv, XV. 1854. LizrBperktun, NATHANIEL. XVL Ueberdie Psorospermien; Miiller’s Archiv. f. Anat. u. Physiol., 1854, pp. 1-24, 349-368, pls. 1, XIV. XVII. Sur les psorospermies; Bull. Acad. Roy. Belg.,1854,xx1, pt. 1, pp. 160-168, 1 pl. XVITI. Notice sur les psorospermies; Bull. Acad. Roy. Belg., 1854, xx1, pt. 2, pp. 21-23; reprint, pp. 1-3. ; 1855. LizBerkwtun, N. XIX. Les psorospermies des poissons; Mém. Cour. et Mém. Sav. Etrang. Acad. Roy. Belg., 1855, XX VI, pp. 36-38, pls. X, XI. 1858. Hecker (Jacop) and KNER (Dr. RUDOLPH). Scoxe Die Siisswasserfische der 6streichische Monarchie, Leipzig, 1858, p. 12 (see p. 186.) 1863. BaLpBiant, Prof. GERARD. XXI. Sur Vorganisation et la nature des psorospermies; Compt. Rend. Acad. Sei. Paris, 1863, Lv, pp. 157-161; Gaz. Méd. de Paris, 1864, x1x, p. 146. [Article erroneously headed Sallisan in the Gazette Méiicale, but correct in the index. The two articles are nearly, though not quite, indentical.] 1866. BALBIANI, G. XXII. Recherches sur les corpuscules de la pébrine et sur leur mode de propaga- tion; Journ. Anat. et Physiol., Paris, 1866, 11, pp. 599-604; Compt. Rend. Acad. Sci. Paris, 1866, LX1II, pp. 383-391. 1867. BALBIANI, G. SXITT. Etudes sur les maladies psorospermiques des vers 4 soie; Journ. Anat. et Physiol., Paris, 1867, tv, pp. 263-276, pl. x11; Compt. Rend. Acad. Sci. Paris, LXIV, pp. 574-578, 691-694, 1045-1049. BrssELs, Dr. E. XXIV. [Om the Psorosperms of Perca fluviatilis]; Tageblatt d. 41 Versammlung deutsch. Naturf. u. Aerzte in Frankfurt’a. M., 1867, pp. 71-72. 1874. CLAPAREDE. XXV. In Lunel’s Histoire Naturelle des poissons du bassin du Léman, Geneva, pp. 113-114. 1875. WITTMACK, Dr. L. XXXVI. Beitriige z. Fischerei-Statistik d. deutsch. Reichs, Berlin, 1875; Diseases of Fishes, pp. 190-192. SCHNEIDER, AIMEF. XVII. Archiv. de Zool. Expér., Paris, 1875, tv, pp. 548-549. 1877. Souter, Dr. XXVIII. [‘‘Psorosperm” of Crocodile; mention only]; Jahresber. schles. Ges. f. vaterl. Cultur, LIV, pp. 44-45. 1879. 1880. 1881. 1882. 1883. 1884. 1885. 1886. THE MYXOSPORIDIA, OR PSOROSPERMS OF FISHES. 125 Bibliographic reference No. LEUCKART, R. xX XIX. Die Parasiten des Menschen, Leipzig and Heidelberg, pp. 230, 241, 246-247. Ryper, Prof. JOHN A. O:O.@ The Psorosperms found in Aphredoderus sayanus; Amer. Nat., 1880, xiv, pp. 211-212, figs. 1, 2. GABRIEL, Dr. B. XXXII. Ueber die in d. Harnblase d. Hechtes sich findenden parasitischen Gebilde ; Jahresber. d. schles. Ges. f. vaterl. Cultur for 1879 (1880), Lv, pp. 188-195; review Journ. Roy. Micr. Soc. London, 1882, 11, pp. 358-359. ButTscu ui, Prof. O. XXXII. Myxosporidia; Zoolog. Jahresber. for 1880 (1881), 1, pp. 162-164. SXXITLI. Beitriige zur Kenntniss der Fischpsorospermien; Ztschr. f. wissensch. Zool., 1881, XXXV, pp. 629-651, pl. 31; abstr. Biol. Centralbl., 1881, 1, pp. 294-297, and Journ. Roy. Micr. Soc. London, I, p. 766, and Zoolog. Record for 1881 (1882) xvi, Prot. pp. 34-35. BUrscuii, O. XXXIV. Myxosporidia; Bronn’s Klassen u. Ordnungen d. Thier-Reichs, 1882, 1, pp. 501, 590-603, pl. 38. BALBIANI, G. XXXV. Myxosporidia, ou les Psorospermies des Poissons; Journ. de Microgr., 1883, VII, pp. 143-147, 197-204, 270-281; numerous figures, BALBIANI, G. 4 XXXVI. Légons sur les Sporozoaires, Paris, 1884; Les Myxosporidies, pp. 120-124, pl.iv. Reprint of preceding. [Erroneously attributed to Dayaine, in Leuckart’s Parasites of Man, 2 ed., 1886, p. 191.] LADAGUE. XXXVI. Article in Petit Ardennais (July) upon the epidemic among the barbels in the Meuse; also in Réveil des Ardennes of August 22. Neither of these articles was seen (both fide Railliet, 1886, p. 137). ZSCUOKKE, FRITZ. XEXVITI. Psorospermies de Coregonus fera; Archiv. de Biol., v, pp. 234-235, pl. x. MEGNIN, P. XXXIX. Sur la réle pathogénique de certaines psorospermies; Bull. Soc. Zool. France, 1885, X, pp. 351-352, with figure; abstr. Journ. Roy. Micr. Soc. London, VI, pp. 265-266. XL. Epidémie sur les Barbeaux de la Meurthe; Compt. Rend. hebdom. Soe. Biol. Paris, 1885, 11, pp. 446-447. [An almost verbatin reprint of preceding; no figure. ] LANKESTER, Prof. E. Ray. XLI. Article Protozoa (Myxosporidia); Encycl. Britan., 9 ed., xrx, pp. 853, 855. KOLrsnikorr, N. F. XLII. O psorospermiakh (miksosporidiakh—myxosporidia) v muskulature rib [Psorosperms in the muscles of fishes]; Vet. Vestnik, Kharkoff, 1886, v, pp. 242-248, 1 pl. RAILLietr. XLITI. Maladie des barbeaux causée par des psorospermies; Bull. et Mém. Soe. Centrale d. Méd. Vétér. Paris, 1v, pp. 134-137. LEUCKART, R. XLIV. Parasites of Man, 2 ed., 1886, pp. 195-197, figs. 98, 99. LEUNIS. =LV. Synopsis der Thierkunde, 1886, pp. 1137-1188, figs, 1118-1119, 126 1886. 1887. 1888. 1889. 1890. REPORT OF THE COMMISSIONER OF FISH AND PISHERIES. Bibliographic reference No. RAILLIET. XLVI. Eléments de Zoologie Méd, et Agric., Paris, pp. 167-168, fig. 72. BORNE, MAX V. D. XLVII. Haudbueh d. Fischzucht u. Fischerei, Berlin. p. 211, fig. 215. Kocu, ALOIs. XLVIII. Encyelop. d. gesammt. Thierheilkde u. Thierzucht, Wien u. Leipzig, 1887, Iv, p. 94, fig. 668. Moniz, R. XLIX. Observations pour la révision des Microsporidies; Compt. Rend. Acad, Sci. Paris, 1887, civ, pp. 1812-1318. PFEIFFER, Dr. Louis. L. Beitriige z. Kenntniss d. pathog. Gregarinen, I; Ztschr. f. Hygiene, Leipzig, Ill, p. 475, fig. 2e-g. PFEIFFER, L. LI. Beitriige z. Kenntniss d. pathog. Gregarinen, II; Ztschr. f. Hygiene, Leipzig, IV, pp. 403, 408-409, 417-420, 428, 435. HENNEGUY, F. LII. Contribution a lV’étude des sarcosporidies; note sur un parasite des muscles du Palemon rectirostris; Mém. publiées Soc. philomat. Paris 4 V’Oceas. Centen. Fondation, 1888, pp. 165-171, figs. A-D; abstr. Jour. Roy. Micr. Soe. London, 1889, p. 76. VOLKSZEITUNG, COBLENZ. : LITI. No. 209, Sept. 11 (year?). Notseen; fide Ludwig. Lupwie, Dr. HuUBER?. LIV. Ueber die Myxosporidiumkrankheit der Barben in der Mosel; Jahresber. d.rheinischen Fischerei-Vereins Bonn, 1888, pp. 27-36; and separate, 10 pp., figs.; abstr. Centralbl. f. Bakt. u. Parasitenkde, 1889, v, pp. 419-421. Date jide Pfeiffer (Virchow’s Archiv. f. pathol. Anat. u. Physiol., 1890, CXR, D0) TURAN TE CAy LV. Ueber ein Myxosporidium aus der Gallenblase brasilianischer Batrachier ; Centralbl. f. Bakt. u. Parasitenkde,! Jan. 12, v, pp. 84-88; figs., ibid., Feb. 19; abstr. Journ. Roy. Micr. Soc. London, 1889, p. 537. HENNEGUY, F. LVI Psorospermies; Dict. Encyclop. Sci. Méd., Paris, 1889, xxvul, pp. 771-776. THELOHAN, P. LVI. Sur la constitution des spores des Myxosporidies; Compt. Rend. Acad. Sci. Paris, crx, pp. 919-922; abstr. Journ. Roy. Mier. Soc. London, 1890, p. 194. THELOHAN, P. LVIII. Contribution & étude des Myxosporidies; Annal. de Microgr., Paris, 1890, II, pp. 193-213, pl. 1; abstr. Journ. Roy. Micr. Soc. London, 1890, pp. 346-347. THELOHAN, P. LIX. Nouvelles recherches sur les spores des Myxosporidies (structure et déve- loppement); Compt. Rend. Acad. Sci. Paris, cx1, pp. 692-695; transl. (un- abridged) Ann. Mag. Nat. Hist. London, March, 1891, vir, pp. 304-306; abstr. Journ. Roy. Micr. Soc. London, 1891, pt. 1, pp. 55-56. [Practically identical with preceding. ] SipLey, WALTER K. LX. Psorospermia in relation to tumor formation; Trans. Path. Soc. Lond... X11, pp. 322-325; abstr. Baumgarten’s Jahresber. Fortschr. Lehre Pathog. Mikro-org. for 1888 (1889), IV, p. 322. (Unnnportant; psorospermosis of carp found labeled ‘‘multiple sarcoma.” ] 1 Misquoted by Pfeiffer (1890, infra, p. 49) as ‘Bacteriologisches Centralblatt, 1890,” THE MYXOSPORIDIA, OR PSOROSPERMS OF FISHES. LO Bibliographic reference No. 18y¥b. LecLeRca, Mile. LXI. Les microorganismes intermeédiaires aux deux régnes, Myxosporidies; Bull. Soc. Belg. de Microse. Bruxelles, 1890, xXv1, pp. 100-102, 109. PFEIFFER, L. LXII. Ueber einige neue Formen von Miescher’schen Sehliiuchen mit Mikro-, Myxo-, und Sarkosporidieninhalt; Virchow’s Arch. f. path. Anat. u. Phy- siol., Berlin, Cxxu, 557-564, pl. 12, tigs. 1-3; review Centralbl. f. Bakt. u. Parasitenkde, 1892, x11, pp. 110-111. LXIII. Die Protozoen als Krankheitserreger, Jena, 1 ed., pp. 2, 25-27, 30-38, 41-47, 74-75, 98-99, figs., plate,! myxosporidian figs. I-v. RaIvuier, M. A. LXIV. La maladie des Barbeaux de la Marne; Bull. Soc. Centrale d’Aquicult.? Paris, (about September 1) 11, pp. 117-120. MINGAZZINI, P. LXV. Sullo sviluppo dei Myxosporidi; Boll. Soc. Nat. Napoli, September 23, 1890, Iv, pp. 160-164. THELOHAN, P. LXVI. Recherches sur le développement des spores chez les Myxosporidies ; Compt. Rend. hebdom. Soc. Biol. Paris, Nov. 14, 1890, 1, pp. 602-604; abstr. Journ. Roy. Mier. Soc. London, 1890, pt. 2, pp. 194-195. 1890-1891. PeRuUGIA, ALBERTO. LXVII. Sullo myxosporidie dei pesci marini; Boll. Scientif., Pavia, 1890, x1, pp. 134-139; 1891, x11, pp. 22-25, 1 pl. 1891. THELOHAN, P. LXVIII. Sur deux sporozoaires nouveaux parasites des muscles des poissons; Compt. Rend. hebdom. Soc. Biol. Paris, Jan. 23, 1891, 111, pp. 27-29; Compt. Rend. Acad. Sci. Paris, 1891, Cx1r, pp. 168-171; Journ. de Microgr., Paris, 1891, Xv, pp. 145-147. GARBINI. LXIX. Contributo alla conoscenza dei Sarcosporidi; Rendiconti della Reale Accad. de Lincei Roma, Feb., 1891, vir, pp. 151-153, figs. Linton, Prof. EDWARD. 1 Epi. <) On certain wart-like excrescences occurring on the short minnow, Cyprino- don variegatus, due to Psorosperms; Bull. U. S. Fish Com. for 1889 (pub- ° lished June 15, 1891°), 1x, pp. 99-102, pl. xxxv; review, Centralbl. f. Bakt. u. Parasitenkde, 1892, x1, p. 475. LXXI. Notice of the occurrence of Protozoan parasites (Psorosperms) on Cyprinoip fishes in Ohio; Bull. U.S. Fish Com. for 1889 (published July 7, 1891 3). Ix, pp. 359-361, pl. cxx; review, Centralbl. f. Bakt. u. Parasitenkde, 1892, XI, p. 475. PFEIFFER, L. LXXIiI. Die Protozoen als Krankheitserreger, Jena, 2 ed., pp. 7-8, 13, 17, 105-110, 114-115, 127-135, 164-165, figs. 43, 45, 52-57; review, Centralbl. f. Bakt. u. Parasitenkde, 1892, x11, p. 168. 1892. THELOHAN, P. LXXIII. Note sur la Glugea microspora; Compt. Rend. hebdom. Soc. Biol. Paris, Feb. 5, 1892, tv, pp. 82-84. 'In the second edition (1891, infra, p. 7) Pfeiffer says the plate is rendered obsolete by the sub- sequent discovery of the swarm-spores. *Misqnoted ‘‘d’Agricult.”’ (Pfeiffer, 1891, infra, p. 105.) $Date of distribution fide records of U.S. Fish Commission. 128 1892. 1893. REPORT OF THE COMMISSIONER OF FISH AND FISHERIES, Bibliographic reference No. KonotTnerr, A. LAXIV. Myxosporidium bryozoides; Ztschr. f. wissensch. Zool., 1890, Leipzig, April 5, 1892, Lin, pp. 591-596, pl. 24; abstr. Journ. Roy. Micr. Soc., 1892, p. 379. WELTNER, W. LXXV. Myxosporidiensporen in den Eiern von Eso lucius; Sitagsber. d. Gesellsch, Naturf. Freunde Berlin (about May 1), pp. 28-36, figs. 1-16. Krust, Dr. WALTHER. LXXVI. Der gegenwiirtige Stand unserer Kenntnisse von den parasitiiren Protozoen ; Hygien. Rundschau, Berlin (May, June), Il, pp. 359, 361-362, 368, 475-476. THELOHAN, P., and HENNEGUY, F. LXXVII. Sur un sporozoaire parasite des muscles des crustacés décapodes; Compt. Rend. hebdom. Soe. Biol. Paris, July 1, 1892, rv, pp. 585-588; Compt. Rend. Acad. Sci. Paris, 1892, cxrv, pp. 1552-1555; abstr. Ann. Mag. Nat. Hist., x, 342-344; and Journ. Roy. Micr. Soc., 1892, p. 626. HENNEGUY, F., and THELOHAN, P. LXXVIII. Sur un sporozoaire parasite des muscles de lécrevisse; Compt, Rend. heb- dom. Soc. Biol. Paris, Aug. 5, 1892, Iv, pp. 748-749. ENGLER, A., and PRANTL, K. LXXIxX., Die natiirlich. Pilanzenfamilien, Tieipieies 1892, Liefre. 76. THELOHAN, P. LXXX, Observations sur les myxosporidies et essai de classification de ces orga- nismes; Bull. Soc. philomat. Paris, 1892, Iv, pp. 165-178; abstr. Braun, Cen- tralbl. f. Bakt. u. Parasitenkde, Dec. 2, 1893, XIv, pp. 737-739. HENNEGUY, F., and THELOHAN, P. LXXXI, Myxosporidies parasites des muscles chez quelques crustacés décapodes; Annal. de Microgr., Paris, 1892, Iv, pp. 617-639, pl. Iv; reprint, pp. 1-23, original pagination; abstr. Braun, Centralbl. f. Bakt. u. Parasitenkde, Dec. 2, 1893, xIv, pp. 739-740. THELONAN, P. LXXXII. Myxosporidies de la vésicule biliaire des poissons, Especes nouvelles; Compt. Rend. Acad. Sci. Paris, 1892, cxv, 961-964, 1091-1094; abstr. Journ. Roy. Mier. Soe., 1893, pp. 198-199. PERRIER, EDMOND. LXXXIII. Traité de Zoologie, Paris; Myxosporidies, pp. 459-460. BRAUN, M. LXXXIV. Bericht ii. thierische Parasiten; Centralbl. f. Bakt. u. Parasitenkde, x11, pp. 96-97. THELONAN, P. LXXXV.- Altérations du tissu musculaire dues 4 la présence de Myxosporidies et de microbes chez le barbeau; Compt. Rend. hebdom. Soc. Biol. Paris, March 10, 1895, Vv, pp. 267-270; abstr. Braun, Centralbl. f, Bakt. u. Parasitenkde, Oct. 20, 1893, x1v, p. 532. OHLMACHER, Dr. A. P. LXXXVI. Myxosporidia in the common toad, with preliminary observations on two chromophile substances in their spores; Journ. Amer. Med. Assoc., May 20, XX, pp. 561-567, plate, figs. 1-3. GURLEY, R. R. LXXXVILI. On the classification of the Myxosporidia; Bull. U.S. Fish Com. for 1891 (July 15, 1893), x1, pp. 407-420; review, Braun, Centralbl. f. Bakt. u. Parasiten- kunde, Jan. 16, 1894, xv, pp. 86-8. PFEIFFER, L. : LXXXVIII. Der Parasitismus d. Epithelialearcinoms sowie d. Sarko-, Mikro-, u. Myxo- sporidien im Muskelgewebe; Centralbl, f, Bakt, u, Parasitenkde, Aug. is 1893, XIV, pp. 118-130, 1 pl. , ————E eC % 2 THE MYXOSPORIDIA, OR PSOROSPERMS OF FISHES. 129 Bibliographie reference No. 1893. STicKER, Dr. ANTON. LXE SIX, Ueber Infectionskrankheiten bei Fischen; Archiv. f. Animal Nahrungs- mittelkde, KéIn (about August), vil, pp. 121-124. WHINERY, Dr. J. B. SC. Some additional notes on a myxosporidian infection inthe common toad; N. Y. Med. Journ., Dec. 2, 1893, Lvit, pp. 660-662, 1 fig. RAILLIET, A. XCL Traité de Zoologie Méd. et Agric., Paris, December, 1893, pp. 157-160, fig. 77. 1694. THELOHAN, P. XCIL Sur les affinités réciproques des Myxosporidies; Compt. Rend. Acad. Sci. Paris, eb. 19, 1894, cxvill, pp. 428-430 (abstract, p. 275.) b. The literature by authors. [Bibliographic | Bibliographie Author. Date. reference Author. | Date. reference number. || | number. Palbianieeeece co sence eee 1863 | XXTI. Wey die aes! s2suee secs | 1851 | XT. [aie eee eee 1866 | XXII. Lieberkiihn..........------ 1854 | XVI. 15h) Me ae eR E eee 1867 | XXIII. DO’ essetiasa: ahesease 2 | 1854 | XVII. Died Se eee 1gs2) | XXXV: DOP ey et es a | 1854 | X VIEL. Tine ee ee 1884 | SXOXGXGV Ls DO t nee Cota 1855 | XTX. IBONHGIB coos orinca cs cisesiee en 1867 | XXIV. HINTON eee te eee ee | 1891 LXX. Nar ae ae 1886 | XLVII. ie cps. Soe er a ah he | 1891 | LX XI. Sette eapee Sa pee See SSOS yy De ReXONCIOVE Mii Wan diwips scat sacetcce oan | 1888 | LIV. Tone ee LAr) VeNONEX TEs) v0 i Timtigs shoe cat! as | 1889 | LY. eee Ae. t, 1881 | XXXII. |; Mégnin.........-.......--- | 1885 | XX KIX. WOess oe estes ee newts es 1882 | XXXIV. | AD OWS E Hise Shook eee | 1885 | XL. @lsparcdelseseee se o-sea--=- 1874 ; XXV. | Mingazzini ----............ 1890 | LXV. Berens osc on Fe 1842: VI. [Monten alt tea ie kee. © 1887 | XLIX. Sap 1845 | X. | Miiller...... aetT bat tee 1841 | IIL. Engler & Prantl...-..-.... bck Pop 1 0: B-AN IMDN O | Pe ese 184: | IV. Se OSS sees ee See 1880 : XXXTI. DO 2 ACs Fe yale Cee ys 1841 | V. Ae a es 1891 | LXIx. See ES Pinaeanes SCY 1843. |. VIII. GiUme Re cess n ete cana = Se 1838 1 & Ohlmacherisoecos-- seoeeees 1893 | LXXXVI. Wee aecee oe a5 See ie 1841 | II. | Penner ci. se(s os csac.ccseeeies 1893) >| He Noxexende (GH eee cadesorbasqnecsad 1893 | LX XXVIII. ]\ TSR Ch eo epcosoocmanss ae 1890-91) LX VII. Heckel & Kner...-.------- 1858 | XX. Bioiiermas > cee gssekh- er li, ABR aie Henneguy (see aiso Hen- WOM neste. 5.52 seen | 1888 | LI. neguy & Thélohan; Thé- 1D YESS st one nee eee 1890 | LXII. lohan & Henneguy)...---. 1888 | LIT. DOs 25-2 essences theses 2 1890 | LXII. Disa. fos muse comccaes 1889 | LVI. | WO se ssscecceis see's eees 1891 | LXXII. Henneguy & Thélohan -...| 1892 | LX XVIIL. | OSes eer eo sh Ase oi 1893. | LX XXVIII. Dees ssondapeoaeeEose 1892 | LXXXIT. | Prantl (seeEngler & Prantl) Kner (see Heckel & Kner) NW iRmibtieies dccsose-. ale. 51 1886 | XLII. Tithe 1a8% || LWT, [eM Sites meee 229.2) 0! 1886 | XLVI. Kolesnikoiy + cos tsss- cee 1886 | XLII. | Mottstees sts. ae 2 scaceu- 1890 | LXIV. inroineit saa tece= saan 1892 | LX XIV. | DO} tes astens aisles clos 1893. | XCL iA eee eee ASOD ps STEKO Vor A ll Rearrere ee ome tee tk 1843 | VII. Mamnpae..pcsosse 4 kN ss Ae TSEAS WSORERCWDES (0 UCL eer aet yee APN 1843 | IX. Pankester i002. 02.02..45. 1885 | XLI. [eerscrs 20052 SOAP en 1852 | XIII. Mieclercqe i= tos eli secaces 1890 | LXI. | IRODINE a aaee ee ee UL ee 1853 | XV. Ween ekanticc ste o an 5c 1852 | XIV. | Ryder teases eee. ee 1880 | XXX. WO Paaeesiatia<-icise-sc> = 1847 | (See p.—). || Schneider-...-...-..2..-..3 1875 | XXVII. WORet sae sence sae 1879 | XXIX. |sipleysaeemererc ares ors 2= 22 1890 | LX. WO see aes ce icietececes 1886 | XLIV. | Ol were peseirs cinvie cee ee Seale 1877 | XXVIII. LOGUE) acces bad sade aseeeae 1886 | XLV. MMICKON wtesertece s-ucdese se 1892 LXXXIX, Leh a 1851 | XI. | | | 130 REPORT OF THE COMMISSIONER OF FISH AND FISHERIES. b. The literature by authors—Concluded. Bibliographic | Bibliographic Author. Date. reference Author. Date. reference number, || number. Tara a | Thélohan (see also Hen- || Thélohan (see also Hen- neguy & Thélohan; Thé- | | neguy &Thélohan:; Thé, lohan & Henneguy) ------ 1889 | LVI. | lohan & Henneguy) -..-.- 1893 | LXXXV. Doe eee he ee Aen) EERE. 1°) wile, ) Dios oeaueal eee en 1g94 | XCII. TD Of eels p ais sec see 1890 | LIX. || Thélohan & Henneguy.-.--- 1892 | LX XVII. IUGR SS each coos acpessoaee 1890 | LXVI. || Volkszeitume:-.-2 22. 2-222 = 1888 | LILI. WO) ssa5sas0c cnsse50s55¢ | SSE >) SexeVvennl Wisline Ween sees aac eer | 1892 | LX XV. "Die te oe a | 1992 | LXXITI. Wihineryse ue. eee ee 1893 | XC. DOs Me Cee eeu cet 1892 | LXXX. Wittmackit-cere pice eemnas 1875% |) eokovels Wo srehes see eee Mee 1892 | LX XXII. Vischokk@a=< 4o=584- sees ace 1884. | XX XVIII. TABLE SHOWING THE DERIVATION AND EQUIVALENCE OF ALL FIG- URES IN THIS PAPER REPRODUCED FROM PREVIOUS AUTHORS. The tollowing table shows the equivalence of all figures in the litera- . ture, including those of species formerly considered myxosporidian but now rejected. Figures to the right are copied from those farther to the left on the same horizontal line, and those copied in this paper are, in all cases, taken directly from the original. Further, wherever several series of letters or figures (indicated, for economy of space, as *‘a—m” “1—- 16, etc.) occur on the same horizontal line, the individual members of such series correspond always and rigidly each to each, that is, a to a, b to b, 1 to 1, 2 to 2, or 7 to 10, 8 to 11, ete., as the case may be. To save space all intermediate columns not required on any particular page are omitted from that page. Such omitted columns will of course appear on some other page, and their relative positions in the full series of illustrated articles represented in this table, are indicated by the bibliographic reference number (Roman numerals). Plate numbers (heavy type) are inserted only where absolutely necessary to prevent ambiguity. After much study of the literature certain figures can not now be placed with any certainty. They are those to which no species number corresponds in the table. It will be seen that they are principally some of Pfeiffer’s and Balbiani’s and are mainly to be distributed between the two probably very distinct but at present not very clearly delimited species habitant on the tench, Myxobolus piriformis and M. ellipsoides, On the plates I have thought it best to reproduce the groups of figures entire and to leave to the future the apportionment of the individual figures, and will only add that in the synonymy of M. piriformis and MM. ellipsoides 1 have ventured on a taxonomic guess, the dubious figures being separated from those definitely placed by a period or a paren- thesis, THE MYXOSPORIDIA, OR PSOROSPERMS OF FISHES. 131 Table of equivalence of figures. a Ss : —] N > a 4 4 : . ia 4 =) 5 | ro 4 a S| 4 4 : : Be isl & = ey - rf rd : > Hi qi q A ls Cpe 9 an ae = PARA ees ‘SF = 2 = =? 2 | - oo (oo) a or «a Mi au Hy Pe (hoe Sse ce tiee bos | | eee ees 2 ll PEO eden SU a es ee ye = he 3 a be a - i oS bp od S es S n LY 7) a 2 5 3 cI 2 =I fi! = rd r= s C) on Sy D = [=| eS y = cs S 5} a= = 3 2 = a +=} 5 2 i) iS = Bs = =] 2 H 8 fare o = Sa rea is ‘ >) 2 C) S = s o O > sh ele oe = QA = a |) Ss 6S o R 132 REPORT OF THE COMMISSIONER OF FISH AND FISHERIES. Table of equivalence of figures—Continued. a = & 4 = ot her learn Vi Mees Palen Be ji eee) lhe ht det aay ete iB |B |o |o le, es ia Fiat Re ia 2S es OSI NY See eae ee OH ate a au i= 4 Ss none) al tea |e > eS me AK AB) eh | eo |ed| 2 | ae | Se [a4 eel ea | 25 | 5 la ad bd rd pf a 3 re on on ok lakh] & ei oH ae i] J A 2 bq i ‘ S| o ies A ‘ or Bi 5 Sale Sara bd: a Ses Cee eee ae oA [aa OOD DEC Ag ee aN pirate) Word] mee stee HRS Plea! Mi espace 4 H oa) | (a —Q —Q Na ld | 4 a ca) PAD Arf ay I Pages SRP 1A a I et ee |S ee ae) Pee Se tehce see Sa etete siete rel lo ratate sol ferlotavote | Sreternvere ciel] eiate estates |e ctatots oy svc] ete atete Solodgeoollossociollossaccs i G8 | eaees 668, 1 0 AG ieee 668, 3 |.. aha DE RD LR 668, 2 |... Cy Sil ee ral se re ee ee ey el mila esl Retereloemereeeeeioe ct Sasa eee 2 Oh RGD wae | AON Eee el eee ee oe ie Bylo aor ace lapel aeiese | retorel | te rere | iase eaters] ete ete dens 7 UO Vi a fs al | SIP |e heel ba ig | Be Pa a Tt iat Bayi] al TS Een rere] ee | ee pn A eee S4- Gri Mt eS alise acceleces|seleemalen Sse \SSesi5 = wb aka (eat sere es rae PRE SN een fal ee eae Cerra Me eee EM eaaTiS gee TICE SEE Eee P| Poti ete ene leer a fet ei | ud Soe A a er Doe alle wd WE Gill cae a lee Alla me CE a ei a (a OR es fees al meas as ea ct aa Sa SEER IR WRI | SERS 107] Ree alle eS ae a | a | Be | ban 5 | eo rele Le Fcc tPA aro) Mikael] vk Se ee ae nel ROR ete Sal a RE 8) TN EG 2 TD |e Se EF aa EN ote a Se a ee | Saeed Pees oe Bierce momen | era rae PSOE ts ewer eee S TS OE eee ee an ae Res terete Se] Mesaia ey Selllecte Siw cil etme Sie 14 AN AR Alea | laeatclesoaco tse sealaise oa el tice es ol OS argh Pe Cm Te a 15 Ps er lear SI ee eo BAU Bayne he |e oo IES ie TI [Ee A acer Pte el ate al Sees Ee AR RR IEA ALU aN AS sD BO TERA: oN a a rE a | BORER SU OEM Asi a iS IAI aL Y 18 ODM 25 Soe SE Ses RE SEN aa a ome Se ae BRO eae aN ye) Sd Mn Sse ek WP yO gee Se re Sa eae ee ae ease ae RS EN Mis eC TRA es SR seth Ae es Dg SNe AEA lis een ae a ee a ea URES TT LE AIS vase eee PYG Rene | eee eee PORE CS Se ee 20 3 SBR ee eres er aaesen lee eis eet 22 Gaaeeerar Basco oscollatece culls EE | Sete pe Sa ee ls sa TE ease el earth aes st eee Sats eens ss allt eG Nea NSS hie MIN a Zee Ba a Pits [Ge etn (Crh owe ANSE REE AUT eed 4 x sect ees See ee | AMR Cee Pine Bee esehal eeeee BOREL ese aoe cl ee ti Wiese hl ie LAS A 2 alle ac 9 LL a Gi SHE GE oe SS NST FE SU (eC ina rat I a et |e eet a Aa Dy (al Nerina ea Dee a EE CONES solace ell EEC Ce AB eae Salt 8 A Oe DQH SS eer WATS ARE Ae RW AAS ae mead ane fd MPR Ae ene ck 2 3 UIE se AE 0\i| BRR olaa a HERS Re eo a Bel te ae Ss [SS ERGO deren, ean eee SO ec AAR a lceil eaeel lM | sal Sa Rare ea Ne aaa ae eae | aia IR SS STC OU Re Rat eR LM CR ee UC ee a Ee RE A a I 32 sls Reeser ee ee ce one at he eM no ro | Eee ae ae Bee el a BO) [saetewt onl] Cae AER FS eae aR es | pel ae x 3 el > |8 ire} S) 3 i?) S a 14, 4a-g| 38 7, 4a 13 43, la | 100 1b 100 46. 3 100 | 47, 2 100 39, 5a 96 b 96 15, 7b 44 c 44 7, 4b-e} 13 15, 2-4 41 5 41 Ga-c| 41 42,11 98 12 98 1l3a-c| 98 32, 3a-c| 74 4b-d) 74 17, la 46 b 46 c 46 2 46 16, 8a 46 6 46 Lo 46 4a 46 b 46 c 46 d 46 6 46 3 46 16, 6a 46 b 46 c 46 d 46 e 46 17, 7a 46 6 46 16, 5 46 1 46 4 46 2 46 44, la | 100 b | 100 2 100 3 100 43, 3 109 4 100 44, 4 100 47, 3 100 5 100 a THE MYXOSPORIDIA, OR PSOROSPERMS OF FISHES. Table of equivalence of figures—Continued. 133 a & Se Vit | s! of oi Not hep igen Wher) ieee Te les & G Tuer [eos S =i See ey eae seca) ipa es sioa (sais |e. |S. Beep ee Ne est eI ge bt | st Se [Teal Get [esi [sgh test fieten Ye liey aS, ao [dhe | go foelsb lob Glad] oF let lelou lo] et] eG ih i r = A eat on oH -~|44 |.0nM © cas Sr | Sh | Bo jas|-sH sls rl as lea sala ie | gh | eH Bbq | Shy | St (Selah eee le | eS STS) ae los SH] SA | BH = = oA \ox|'s OCP 1S | OAs |S) oF aB le oe) ce A | a Me | lai |e I ial jel a Ay 40a-h| 36a-h|-...--- BABS ICA Olacoe sao Hadellec2ae oe DOD eee eel eae Wee seta aa aene Asie d\| ia d| gee | | oe ae BEC oR Alb oe 2] |esl SES xa eset ese ft ae ene Rage gel A20-G\80-Oleso e+ Bere kaye | = SOU oe a rigpe sim oe loan Sele So 4 RSH) e caclemmAcubalguonbeor ASGAD NT S0G20| Veena ae) Genoese ear ae eee feel Zales oodlesdud Becta We aa eay Bee rcy 44q-b| 40a-b]..-..-- ee ae Sees ne S84) Jdlsecd ee oade| een asa Baerans 45a-c| 4la-c|..-.--- HE AScE Acne more sal emere! omer SiS]! 3c] feo Sie aller mes Pasa tose ei peice pcre 6la-e| 42a-e]....--- jonesfas SH Sacleeee aoe badle Sia abae Me BeGaele saul lomeqciaet 62a-c| 43a-c|..-..-- Ba Geesotae - mL rapes Slee Si all = eal Cae aa Oe he ee laspuerscte Bir) Cele Sine IAP On eee aoe Scelibcisg Ee ooslacs sel eciad esac esac lnce peel eaceceicia 64a-d| 45a-d|.--.. .- Fadel ie thea CBE Salers eotoe - Sl eee ie Pore Meer eee eel ee ecb ee 64e-g| 45e-g)------- Seclladecc Sea arial eee ccs ees ieee ea al eae Ce eae A al Ie Ue byt) EXD. Se Aes e|Becelancoeliaardiesslie aeons By nel bonne lens east i eesti etc 66a-f| 47a-f ....-.- PL Sebo sts ae yA Pee oles |saeeblase ee Auncslseecunal sais elle poe ee OM A UC Eel ite alba alel Wace duck vw Beate pete | eteyacll estate Sr fal aA tl Hee orit eerie neers (menial boise ke aa ia tS BUNS Se Bees Ieee | keke eI |e] ease lereysese| setae eet eels Ra ed (A od ee an ese TGC HEN afl (eS Len aes ed cs Mela tall cosets ston a4 AU at Be BAe (OHS Sie eel Pace) Pees sese ote ieee [eae Pea Na seen Mame esate lies se ee ena San ea TNs Be Ie FB ge (ie PF SPST ce ES es IC Bey | Seana RUA Het eee aa licteralietal| eee | Sera cel| eecial eel ose iabee ll cone| Cece leaceseee es el [ee 133-98 (6c clly Ger otal sealloses Boece Os eee eric ae eaten Ener ter ARE SS Be eod Bacecee HE Sa Be ees eee ae i aoese fies ace alee ghd. MAS tee ee ee le ciaeloecees Daas | ee alone at alltacrcyers Soe oe | eae (Sees elak, VES E reek Baee Ges Ssulebe e582 SMe ase (Pe eellacs|hasalbrtses|ae= SEH Sot Gag Re sepeeel aeiseceae SOA Bee aoe Ree reee e Seg boace 4G) eel lesae sae c| seit eel ee ety) Medes peel Me nares, Ie eee te eRe |e ae eee all pete et cate | eS lorevare |lslerere relieve Westar ALAS Bryer ier aarti Bowes wage t ell RE 8A ROA NR eae | obs eel ets etal eral tort ae hea ell eee a SHASe RB eeeel Bseeare See|hore suse lta (meee laa eal teu i shee (bs Sty a eo bee ae BPE | Merete alll crm jaya SAA obec lacrelscel| lal) Beene eseo eal Sacee [ececrsl acca beers Sec eames Sc coletssreallecstsoce alls Sears oac - (HIS Soa Colloct Steel |S aeons cist aoe aeretrci Jean eee te pe cores Beles loca al eel Sens (a teal O |e ae yaa eee ee | eee eee eee er ys Eee Watersian|(<.e= creche Scullesses|lose a epetare'| Cretareyell ined —ebiz.a tetera a | State Sve lievole, ciel lata m eye alee ae eee sonos| azbees| Geeeeee Beee terns eee asese neeseal econ he eer eee tame et eee ol Sey 3ae64) 5-2 Bee Gaceees ec alee ealoe deal leencel eo eellied beta Cee on ae Sks Geeeercd mmoerecs Sbesalaccaodl|onosos EEeolneeraal le ae i ee eee (ee Be SH Peisal Socticllamisboc tad Cheotaceae sob Se) PhS ae beatae eta tsps [2.51 Alls ceid SoeoS Se.4) Cdleneod nee pect Ceee cies ReSeracios Go] Ee ee DEE ee eee se lames eas AWC apsce ot SER Ge. aba dele aee S6AS ees! Basecers Soelerase alae 2 [eespene Paceramtara)| mvenaratt lo O [tac pe srs Sok Seer [Upstate [Ras 2 ke il oehes oa 8 SS Ghe BES Aes Io einai eaters lle so eaves | eate aot ais cil Sealer ee So | Cora cete | te a BESTA Siewiais I[eelaetoe Soe eee Gee 3 eee een eee keel Spe penne bade Mane cced aeaaree se sebee|cepoce Baote selec leeeer pete Ge 7 eves BO Baal ae SEER eyPo err] Sbpr e|desnee Gees Sh eee Eee ee eee eee Obese a eee | ey stya lees Sea [k teas eral = ells age pele See ing Mal ace eee eee aacsoloctsedllbest seelipee casas dled = SAleaeoallo ne 7S eee oo canic sce abe Sel |ARAS oe SoAae A me et Sera AlBeesac ooe Pes 3 ELEN HlaSsecptto. Stora | eses SaReeee fe Salts ee es See ee alone A (Needle stesouanssenuee 35036 AEBS epee cocdioneac|aos Peyalleis ccste Blt Ba Re et Meee ete yan aarti Oates a lin aera | Br ame (ook Poe Sales celeste OM an ts aeel| Gace oe aaa cdocelbeeoorloobeee Stee) ae stete| (== ty| AloedooMimoelnkl erica Ulsecse lacaccor -leabbocad Spee eaeieiata| rales =i=<1) = dane ssaellpas wll vast oral ar (es st Bleraa kis scasa alee taemes Son closbaaol loosed So aieinesa|aeoc(o =| estates I= tata aera Olea el raha tye ll eh pata Brera leei= ciavaliateraincters'|le mate ae 5 ee epee ae LO |es 2/2 | teers ore tensa ane coat bE el i eel een Hie sayelae lata iatellle& =! lato ate lei rara = |lareratel ea rovhe ja Re eae pcebcend Bede gee el eee Sale cal Ae A eee ee era] rs O20 eae | eC Ddodalle. eee Eee ie Ball rarereelllaes cf Ete eave |e re is te MS thyas2| essa baseless ae CBE cle ee See ae en Penh pene I oF i eed RS aes ee eee PA aes cate Soe Aes EASES aD Se ee : 4) Meiaeeloecles|asa ssh Mekal etcealtac tan kab euee eas ee ee settle ee ee sei a Selle -s228 16 wet ele ee ee Sea SS Si) See ene fe sp dleoses| ane sect eoocsiaes eles MLTOAT Sissy Seances See ete ld esseak |S esia| aoe e liane alos 5 ee eho Sree ESE yee Sees ce a aletebae dae GaSb d S548 Eoptaces eerie ees Set [apres teres Beene ee cra) Nee ea ALL ce ee & 43a bp esasel eeane ie [see (eae peameae Iie Bee eee (eed lee eee steel ee: Paar 43b Ren cohs Sal sand wee |i erat Hee Ses cl Poaceae (eee feese el tee esesnese'| eee [ik Ou (|i reel [ee act eye aoe ee teckel Mae dell cetel eccollS icsel [5 oes ee ec ee | a ay. oy lays 2: Ie ee Bee ee Bee |p ER pe OAT a ale aS TA AD ASB ~Nede| S Sees Eerste) eens Yaa cba eranel Saeed lets inaeelnetaecssbeaacteeae.|) 1 oA=ON SoAHKC Sees eee | Eee eer | eras | Seale tere brated |ereaailee .---.| 14A—B] 54A-B Gece| toe ee eee ae Bees eet ea ececd| loess bolsocee| baecelaaccol la: alsa iat pst 296] beso Beereas Easel pera =e ofall tars tireltetale some aae slice 16 56 Mesie|| Gecite elec msice =| os selcenealls xe Ne ferall laxnets | eta sista es ererel| Steiaters |lateis ia) [fevlata a's oye 57 Be eral PME | ree sei etal|( se tals Sinseio cue S| Sensi eel icmeron SoA eo ee Seo ee Me tteSi ere Sea edl See ce IS ee) Mee Reed fe ae See slau ealcercelbeeee|) RTa-bhiiteee Bee eto Mello afarmiee| saeeel| scsi ae Eeislarsektc|| ates Sel seecatneoe ase cel) Tabi. aa el eer eet perererailiccvste [clon SGreleeiwws| Sac sc] See aelaoee alec. SW! | ES ahaa mance peceec peepee etsy emer =F Ey OSA ate echt eae el ances aoe eee ae Waren es *See pp. 211, 294. t Sarcosporidian falciform body from the sheep. a 3 = A Su he 5 iS a 21, 1a-h| 49 34, 3a-d | 80 4a-d | 80 28, Ta-b | 57 40, 2a-b | 90 39, 6a-c | 96 21, 2a-e| 49 20, la-c| 49 2a—c | 49 46, 2a-d '100 47, 4a—c |100 20, 3a-c| 49 18, 4a-f | (*) 19, 4 49 18, a v3 26 [249 18, 3A | (*) Be Gy Cae 25,1la | 51 @-Gz| 51 ile 35, 1 81 26 | 81 dt 81 29, 8a-b | 67 EPA a (*) 2 (*) 3 (*) 21,4 (*) 5 49 10, 6a-d| 31 25, 2a-c| 51 42,1 97 9 97 3 97 4 97 5 97 6 97 7 97 8 97 9 97 10 97 81,2 ea 19,5 49 6 49 10, 2 28 34, 2a | 80 b 80 e 80 14, 8a | 42 Fi 42 c 42 d 42 20,4a =| 49 b 49 c 49 d 49 e 49 10, 3a-4 | 28 31, 4 71 CRS (t) 25, 3 51 24, la-h| 51 24, va-e | 51 46, la—b |100 45, 3a-c |100 19, 7,8 | 49 45, la—h |100 P13 POG) 28, 2a-d| 51 45,21 100 ITa-b |100 I1Ta-b |100 25, 4 51 5a-c| 51 134 REPORT OF THE COMMISSIONER OF FISH AND FISHERIES. Table of equivalence of figures— Continued. Thélohan, Korotneff, 1892, LX XIV. 1892, LX X XT. Pfeiffer, 1893, LX XXVIII. Whinery, 1893, XC. Perugia, 1891, LX VII. Weltner, 1892, LXXV. Thélohan, 1892, LX XX. Cuénot, 1892 (see p. 171). Stiles, 1893 (see p. 175). Linton, 1891, LX XI, Gurley, 1894. Henneguy & Ohlmacher, 1893, LX X XVI. | Garbini, 1891, LXTX. | Linton, 1891, LXX. Schewiakoff,1893(see p.176). | Species No. oe bas | e J . . is or - for) on 1 oR PwDH. + THE MYXOSPORIDIA, OR PSOROSPERMS OF FISHES. 135 DESCRIPTION OF GENERA AND SPECIES. Tabular Key. The following tabular key includes all the species, which can by any reasonable possibility be construed as myxosporidian, with their prin- cipal characters plotted out. The order of arrangement is a trifle more artificial than that found in the text. Descriptions of the following species are omitted, as I believe there is no rational chance of their being Mywxosporidia: Psorospermium heeckelit Hilgendorff, 1883. (Parasite of Astacus jluviatilis, Hiickel, 1855, De telis quibusdam Astaci fluvi- atilis, Inaug. Dissert. Friedr. Wilhelm. Univ. Berlin, p. 42, pl. 2, fig. 25A-C; ib. Hiickel, 1857, Ueber d. Gewebe d. Flusskrebses, Miiller’s Archiv., pp. 561-2, pl. 19, fig. 25A-C; ib., Grobben, 1878, Beitriige z. Kenntn. d. miinnl. Gesch- lechtsorg. d. Dekapoden; not seen. Psorospermium heckelii, Bericht d. Gesellsch. Naturf. Freunde Berlin, pp. 179- 181 (not seen); ib., Zacharias, 1888, Ueber Psorospermium hdckelii, Zoolog. Anzeiger, XI, pp. 49-51 (abstr. Journ. Roy. Micr. Soc. London, 1888, vii, p. 240); ib., Wierzejski, Kleine Beitriige z. Kenntn. d. Psorospermium hdckelii, Zoolog. Anzeiger, XI, pp. 230-231 (abstr. Jour. Roy. Micr. Soc. London, 1888, VII, p. 598). This form and the next have never been definitely referred to the Myxosporidia, but Prof. Linton’s bibliography of the “Psorospermie” includes the articles containing them. They have no connection with the Myxosporidia, Psorospermium lucernarie Vallentin, 1888. Zoolog. Anzeiger, XI, pp. 622-623; abstr. Journ. Roy. Micr. Soc. London, 1889, pp. 75-76. See note on preceding. Pfeiffer? states that Myxosporidia were found by Leuckart and Lieberkiihn in the gall bladder and the kidneys of toads. Now, the assertion, in so far as it concerns Leuckart, is, I suspect, an error. It was probably copied from Lutz,* who says: The Myxosporidia are, as it is known, entirely parasitic, and in the large major- ity of cases live upon fishes. The only one of the authors accessible to me who men- tions their occurrence in the Amphibia is Leuckart, who found them frequently in thé urinary bladder of frogs, and also mentions the occurrence of a species described * by Lieberkiihn in the kidney. I have been unable to find any such observation of Leuckart’s, and correspondence with both him aud Dr. Lutz failed to elicit a reference or a substantiation of the statement; so that “ Leuckart” is here prob- ably an error for Lieberkiihn. Furthermore, there is absolutely noth- ing to indicate the myxosporidian nature of the forms described by 1 Bull. U. 8. Fish Com. for 1889, 1x, p. 102. ?Virchow. Archiv. f. pathol. Anat. u. Physiol., Berlin, cxxm, p. 557; Die Protozoen als Krankheitserreger, 1891, 2 ed., p. 134; recently copied by Ohlmacher, Journ. Amer. Med. Assoc., 1893, xx, p. 562. ’Centralbl. f. Bakt. u. Parasitenkde, 1889, v, p. 84. 136 REPORT OF THE COMMISSIONER OF FISH AND FISHERIES. Lieberkiihn.! On the contrary, both his descriptions and figures (which show spores, apparently of two different species, containing faleiform corpuscles) justify the opposite conclusion. And Lankester? distinetly affirms its coccidian nature. Possibly, Pfeiffer? says, a form reported by Kunstler and Pitres* from a pleural exudate of man is perhaps referable here. But from their descriptions and figure it is hard to see how by any possibility it could belong to the Myxosporidia. The smallest spores are 18 ~ “long” and the largest 100 4 In such large spores it is inconceivable that the cap- sules could be missed, and Kunstler and Pitres appear to regard it as coccidian. Further, Pfeiffer says: Also relations exist with a form found in chickens by Arloing and Tripier. The following data will suffice’ for its rejection: Arloing and Tripier’ tell us that they found oval bodies with granular contents, a clear central nucleus, and a sort of “button” at each extrem- ity of the longer diameter. These bodies measure 500 to 550 jz (400 to 450 pv, excluding the * buttons”) in length, and 200 to 220 in breadth. Balbiani, from an examination of hardened specimens, reserved his opinion, but rather believed them to be “psorosperms.” In spite of and after this, the authors tell us that they identified these oval bodies by finding identical bodies in the oviduct of a worm found imbedded in the same situation (cesophageal mucosa); in other words, they are the ova of a worm. It is hardly necessary te go further than their dimen- sions to exclude them from the possibility of being myxosporidian spores. It might, however, be added, that Balbiani would certainly have noted in his Lécons sur les Sporozoaires (1884) such an unprecedented anom- aly as the occurrence of a myxosporidian in a bird. I cannot, perhaps, better place the following remarks made by M. Armand in the way of discussion of Arloing and Tripier’s paper. M. Armand, in concert with Balbiani, undertook, in 1873, the inoculations of “psorosperms” both in warm and in cold blooded animals. The attempt succeeded, and several pieces showing the proliferation and modifications of these bodies transported into organisms very different from their normal habitat were obtained, and preserved in the collec- tion of the Laboratory of General Physiology of the Jardin des Plantes. As the subsequent myxosporidian literature is silent upon this point, it is probably safe to presume either that in this case “ psorosperms ” did not mean Myxosporidia, or, if it did, that the myxosporidian branch of the work proved barren of results. 1 Miiller’s Archiv., 1854, pp. 1-5, pl. 1, figs. 1-19. 2Encyclop. Britan., 9 ed., xrx, 1885, p. 855. 3 Die Protozoen als Krankheitserreger, 1 ed., 1890, p. 49; 2 ed., 1891, p. 135. 4Sur une psorospermie trouvée dans une humeur pleuritique; Journ. de Microgr., 1884, vii, pp. 469-474, 520-526, pl. 11, figs. 1-15; pl. 12, figs. 1-3. °>Lésions organiques de nature parasitaire chez le poulet; Compt. Rend. Assoc. frang. Avance. Sci., 1874, 2d (Lyons) Sess., pp. 810-814. E MYXOSPORIDIA, OR PSOROSPERMS OF FISHES. 137 Parasite of Sygnathus, Pfeiffer, 1891, Die Protozoen als Krankheitserreger, 2 ed., p. 111, figs. 46-49: From a perusal of the deseription and an examination of the figures I can find no evidence of myxosporidian affinities, and have therefore excluded this form. While this paper is passing through the press, I have, however, observed Pfeiffer’s paper,! in which, in the portion devoted to the Myvosporidia, he says: Of the Syngnathus from the North Sea, which the author was able to investigate two years ago in Helder (Holland), the relative conditions have been thoroughly pictured by the author in another place. Finally, a comparison with the following may perhaps not be inad- visable: Csokor, Gregarinosis d. Forellen, Oesterreich. Ztschr. f. wiss. Veterinirkde, Wien, 1888, 11, pp. 56-58. The author says the forms observed were undoubtedly referable to the “oviform and globular Coccidia (Gregarines).” From the general tenor of his description I suspect they were not Myxosporidia, and in any case there is at present no evidence to warrant their admission into the subclass. Hardly any explanation of the table is necessary. The grouping and position of the capsules (and the correlated orientation of the spore) is made the leading character. Next come the other generic characters (bivalve condition of shell, presence or absence of vacuole, etc.). One of the most important uses of this table is to direct attention to the gaps in our knowledge. Thus it will serve a useful purpose in showing readily where work is most needed. 'Centralbl. f. Bakt. u. Parasitenkde, 1893, xiv, p. 124. 138 REPORT OF THE COMMISSIONER OF FISH AND FISHERIES. | Species No. Tabular key. Spore. Vacu- Capsules. Shell. alte Symmetry. 1 only 2 or more in— a 4 <= = | 2separated a £ |e a groups. JES Genera. = lo 2 oe =I = w > > = |eo0] & Bog | on 4 Rlee BR |e] 48 S oh K Ol anee | ses 5° - | Bivalve. | 7° 8! . oe Hi a eat a ly eae tate OD ws | 8 5 = St ar Ro | 8 Sud |e : 2 q a \ea) 2 | Se] AE Ae ae 2 & a So | ick B | HE So | s'| 5 e nea he) oS aa ad ar — ac Le eae >| 2 |23| a | 32 | ae gele |e) off EtG 2a 5) Sek | 20 sie ee oS B S | fp o |a i=) o Ctl AR} So =I o = i) a's a zw |o 3 Si c8 2 ee | es Bis Sse elas a SP on eet lii sey ll © | =) qa}4 4 qi eel eo ewes sme anes einel Ces eeeoeet em mee BEA aoa sass) ne See |S sa5 (TOUUS eENCOLt. NMOL | neha eer |e ee ate em et aetna Appar-=\ | | s=ses.- SAN PAT) == — ssa Snore my xosporidian). ently 0. ently noue Gents) incert, s(prO pda cre yar ose ete | ate eee tel mre elem wal ede en at | ta bly myxosporidian ; spores unknown). 5 LOSS WO Sicewaccucemecinn|(eeclsa2el ewes pest iaci ae nae |pemetisiee eee all heel lalate) eral ea caine ai aBaeaS Gh) Gossabenscdsaradine | lees Sul eea sce eedecelesceecewes ta) seer lence [ete 2 2oe| tea em Wedeae Moeee eect e eek et | Pt] gs A eS Ae | Re ns email Zoli 8 | See Bees joes soe AOS SACO aah A Anerey tes Seeks nae eels nog Moma eeccs| Season eae faseslocdacolfioyacc)iacc oettion ORR OR OHSCCOEGE| Rip aegsel Bcterc rs Samce sl Sicecd| haSSGeecoesa) Sado marry ese Scie ociccn disci: Genus incert. (aber = |=. ..|5 s-|-cccs5|oaceeseeeam =| sas em Ae eee Ne Bee ase Ave| Sener erat Seine ee eater rant Myxosporidia?). I | { TH Tabular key. MYXOSPORIDIA, OR PSOROSPERMS OF FISHES. Spore. Tndex. 139 Vv &p S o Tail. Dimensions. a 7 a i Present. | zy bo a1 2 ; a OS } Single. & & re a : Bee Ss aa : Outline on EB = rd oS = ge = | vertical 2 z. A Ser = 2 Y view. ete ae o| & g n 2 SL psy ety SES a = = w af gq I = 5) | 3) He n ey io 5 a | a= Se q nD 2 =) ° iS = Sle a oo m | . qe an] 7 fern ssh le Ee B= ENS 2 H 5 o 3 3 S S = a ala S) AGS lus en S) ny n Sige a = ei|ale) & Calcauhat (te Su) 2 ROI | Gers it 2 &0 @ | o | a a& | ro | D 1 S) Dm = fH - ~ Pal — = a = io) = a OE are RB o als\ie v = o Lal S y R ml 2 H & aS 73 H mS aw i(P ED) | fa) 4 mAayeis oy O|/o}f% | & A a pee ——— ee | ce teee eee | Seene [eel Ose On Tnd§ P| Vat Ke el LG) ged PNA eee be De Is el Ree Al cee sD ovoid- elongate, rurely spherical. | siensoe ered aeemea eae HN OMOLM CIS 1 Mea. Gi anOle te coc] saice | Saale ew asae eens eee] sae | enters eee esac hanes tally trun-| spores 24; cate,prox-| m icro- imally: spores12. | rounded. eae ate Pee eceeale = Auen hl G te A We royel Wy | eee ete ll PB el eee) epee WO 8 ape S| Sk lar. seas one Lesher bas al eee tes ol [eg Ree eae tA Bt i ae cal [oe PADDY ARS 2 a © Ts Gal Lad Sota | epee Bee steel =| OSLO. = ace cota ena | eee eae ees | Manele otek fee hetrrece oe eee Ment scasee ere loreal ee | ORM stl Oe esi ier Bll eed Geol eed beacad ese leodcl nema eesa ececsciael lla Calta tea (0 pyritorm. balar, 1G. ees s B tara enat veal ne emote As Bel See Eo sore feaniee U eee 2864) a6¢So0| sad beeeece soe ce| Hee geadase | feceec|i Per afemieatals [tate =| cree stele le fama cles eters | sae cfsmten (eee nee. lae clits aceon aaanell oes | e Skiemere sob cl ead Maes Renee se tecel ta Ree creer Ere Reps Leese [Ee a AEF Bi hae Pa I ae Am) PT PY) 2.6os Sal! 2h ae Smeets Oa IER. Ee Ee ees Dee ieee Geese tlle eee PS PASE | AEM ie BU (cee 10 Ses ae ee eee Bee etn Sree Cerne re tapes kine SPN B08 epee atatane ee mere me | eet car lL! yes Ale he pore eG aa | | | ae eae tee eae .--|Top-shaped A GLO), CGH ae 2e| beers ve ELIE ceils Mell ea aa eee 12 ble si tl ee eae i we =| PCireml an es Mugen Cusin=)|5254)eeee | ee easepa eel scree cae|t sacl asec ccmalaesca me -eter. 140 REPORT OF THE COMMISSIONER OF FISH AND FISHERIES, Tabular key. Species No. ~ 2 Myxosporidium. Cyst. | 5 g op Z & 2 z§ Se es Host. Si we as Si ize = . = ize inp.| & 3 Nuclei. 3 23 inant Shape. | Color. So a | ee bs 2 ° ov ° a” & B lee | s ee # | ge | 5 SE Oo =| [=| >) 5) a a a S i ~ oy Ay > | San b OC POOSOe Eee Rae et Reema WE BART a SA ae) Cen Ewe aed Mek tetra St ris... Gregarine ovoid, 65 « long, with a very volumi- | 1to2in Sphor-i|: 222-2. Echinocardium cor- nous nucleus and clinorhombic crystals. diam- | ical; datum. eter. con- taining spores and rest of seg- menta- tion. Spores develop endogenonsly, several within a |.....-..|.-....-.|.------. Gadus morrhua...-- lobule, the latter sometimes with an envelop- ing membrane; spores at first unsplit. Amosboid mass 7°5 to 12 », with blunt processes |........|.....-.-|.--..--- Salmo fario......--- and sometimes a tail; ends clear, center con- taining many dark corpuscles. Breen (oe. a] setae oleate sume care anne leeeeas 2 to 4] Oval..| White.| Anas bos« Apocec by 0°7 7 by 3) Prob-|Blunt,|1,globu-| Appar-|........ con- | Diame-| Glo!n-|Dark ..| Cyclops (in pai... to 20) ably|lobu-| lar. ently trac-| ter10;} lar. lar C. strenuus), By 6;| not. | late, absent tile, | plas Diaptomus cwru- plas- hya- (ef. p. poste-) mode leus, D. richardi. modes line. 179.) ro-pe-| cysts 18 by riphe-| 30-60; 8 to 48 ral. jelongate by 23. tubes 70 by 24. Small and granule-free to larger and granular; | Present; membrane | Abramis brama..--- processes rather sharp; in size not equal to a transparent. blood corpuscele of the tish; granules extremely small, held together by a mucoid substance. Consisting of granular protoplasm; very similar | Apparently no true | Percafluviatilis..-.. to a Chloromyxum. mucronatum; apparently cyst. very variable, oval, lenticular, or dendroidly branched; size 27 to 440 «; with or without a structureless membrane; pansporoblast bi- sporogenetic. : {hose (oA al penta sinraawera| an ebeees| come cs|aueeeas| sac tome omac ==) Ua0tR Oba eee peel ee etal slnistat= bills nieteiciwinia| oie mete = eiel| com ete ee eee cetiie meee eee mene oe eee Lota lota .---... 5.2: ev anable, movements incessant, slow, amoe- |.-...--.|----.---|.------- Leptocephalus con- old. ger. Seno80| Saciseol -aaeee | laooenaer pacteate bseqncea Gactes 2°5 to |......-.|....--..| Notropis megalops- (clus- ters) 7 by 5 Sacee6| Sd5sed|obeocs| Ssarcane Pres- |......../.----.| 1:09 to| Cylin- |........| Gasterosteus acule- ent?? 2°18 by | dzical, | atus. 0-44. | rarely ellipsoi- dal or spher- ileal. — 4 on THE MYXOSPORIDIA, OR PSOROSPERMS OF FISHES. Seat. wi aut..v-avdominal septum. Body cavity ; digest- ive tube. Arr lad ders eitecle- Interstices of mus- cles. Body cavity, abdo- men, thorax, tail, natatory feet, first antenne. Branchie; ? also of heart blood. Branchiz Subcutaneous sue. Subcutaneous | tis- suc. Pathologic efiect. Atrophy of tail | muscles. | Se ee Pathologic Tabular key. Remarks. Spore leathery, con- tents granular, colorless, amber or fuscous yellow, forming indefinite cylindrical, fila- mentous or spiral colonies; rarely isolated. A perfectly typical monocystid Greg- arine. Gregarine stage passed usu- ally in digestive tube. Spores con- tain 8 falciform corpuscles. mass w hitish- yellow, pasty, drawing out into dirty white threads. Spore containing a eentral globule (‘‘nueleus’’) 7 to 11 » in diameter, surrounded by several fine gran- ules. G aus. Psorospermia. -- Lithocystis-..... | Genus incert -.. SoU 0hocce slog teers | Balbiania Genus incert -.- Genus incetrt. - -- 141 Species. scizne-umbre. - sp. incert sp. incert rileyi sp. incert -| sp. incert sp. incert sp. incert congri * “ Myxosporidium ;’’ name not in good standing, see p. 206. Species No. 13 142 REPORT OF THE COMMISSIONER OF FISH AND FISHERIES. Tabular key—Continned. Spore. Capsules. Shell. pares Symmetry. lonly.| 2 or more in— a c S | 2separated aa £ ie A groups. a Genera. Bale 2 os = H 5 co b 5 = |o® S ec Y iy A |e50) ag | a ’ & of H o'|78| 2 a2 | ~ .| Bivalve. a S ~ a a = =~ + OL =o o a =) Sin S Bs on 2 ° "A 5 E ° nD De ~ a cite ae a aS DQ Gq a oo co 5S Zia So I 2 = =| A Ae T a es aeme ELE & Be sa) ne A Oo >-4 = =H PS) eA | a, ras} $ H fae = Soma Sa 5 5 ° H ° ~ Ss |e = Ss Lo =I SS a oO a 3 > |o iS) ORE aa eR ro a o ~ o Co ial q H r=] 7 3) sl sa ~ a) a i=) 2 {9 on A qd =| A S A | & Rn O10 a (de 4 A qiniad es) tis = = | 148) (Gennsin cert.((MH OSU, ies [ See | ae ee. ase Pees | eee eee es selec Br RY A Be acimye ese as possibly all, myxo- sporidian). 1G eee (ty Ree ee Se Sar ss | AS Cap STU OSA ee ee Pere eeitee sera eee ose) cane Yee dl ete ee ee eee 16 D3 O Wise Satects ae ceie 2 Pe eee esos) Sabcm sl seas loot Oo oSan eens caer es (|S = aoe en . 17 SEO) Lop aan aoeece Ue dbseeselbcateale Ss nciel|sos-osboerad Passer | eeriseeie- ose! secs: | 18 EO cesees anne UE Decal ere ones Meee | Sere somal cts oe z 4o atel[lacieidiats loreal eeeraeee f Oe ALO ee ae eee Se he os SMa ESE Satbeiae er ae tale Spa eS TLCS came 2 Be ae eee es fae | DAVY | [eee oy Seto AE ARS be Pe ae CE sel iat tell eae Ae pe eh een ee eee rel act eee eee ys te| see 2 21 ESCO Roce oe cieeenee pet | Oe 2 oh eee eee elem BOF soaee = » Be eee Beseuc 22 5200 Secu ns sees, Meat Aes Seessa Bor ton eioslacossacboraa esses Pe Pe eee sel Bor Se 23 Se Sass SS tes tel (eek eat EE 9 font onthe Be en SPE rio eric. 24 3 (eee See a 1 | BS36e- HORS eis Rol eet OOS Aietses test reel SAC so tym eS occ Dist Same Weesessaesen ae Pa sel A bestia eh es a Ne ete Pre Meese eee Al Ae | ZOulee iy OR pOTIC Uo ee Ee ese eel ee Oe tee 2! ooealh ota ane { uoles.”’ 743) S8Sn0 0) gape sasesesSe alter sees dlemer ce oom Os Calle ea Soir DW Bepeeeesoe asecce ITI} Thelohania........ 4 THE MYXOSPORIDIA, OR PSOROSPERMS OF FISHES. Tabular key—Continued. 143 Spore. 0 , } : Index. 3 Tail. Dimensions. x | 2D al isi Present. a a ) i=) a Atle Single. S i) a = oe shyt hess Sy iser eg 4 Outline on ee A Z os s Be 3 | vertical ) =| : 8 Sie = we) L view. et =) © A = e 13 =1 Q =5 S 5 € AS Ee : 3 q 3 hens) 5 cS) = ion wes a a oO 5 sS : os | = 2 5 D ) Q ~ zlioae}°e Bin © ) ec Oo} S aa a wa | mn | . i ~ Z, a! He =I cle! a o ° S B a, 2 8 == Wa ima ee é slela| 8 eet [ice tee cl ied tas Fahy SO Sp S| | & Zz may Wes a ice Rl es = |S Seats Ins a ro Wa ba = © ais cs 3 iS =) ani ie) o | 4 | oO a a| a = A 5 = bjiA |A 4 AlA}A| & O,/O}] & /a a |e a | [eee : Sy are) ai =| ee sasellpesic Ss pee eepeseeecr lt Seerecesocess seelie Pcie SSBCMEeoS seed ace toca oa Seccsel[Eoceds 14 ace ecasnel bese pees sereseeal Secosiscoocmal |S as Very Shapeess |e be se cea eesees 15 long; ex- truded by gly- cerin SEAR RAS oe Sad wateaeeme AEE Cee rae : SAR BSE Seve Aan e Be ena eee Cyl IP Se 16 sedlezomer| base Mebeesed S66 | SeoriSopeaccs) Bese ed A (eS oa a aro) ae [el ee ay a NL 17 bal ares ee | Sena te matiama| Peres Skee mn [ Sees 2 Ee AS eescae Coe Saea| acm aaa Cee 18 eae eae aah oe BSS ee See ee ees ener OF rl eel CSE ICE E] etter Teel (crenata || aro woe hho ie 19 ae S| ae 2 SHEE Se SOE SSO ESE SE emacs SN er eee GRE eE eed ne Memorial sara tee aor 20 kata eee SR Et soameeecet kis cesascee heels LASAC RLS Ss 3) Sage BEA OSS ep DL 2538) eras pee 18 BER REE Ges] MERE ree eee | tein) pea eas aed rer cheba DSM Sova ot ane al lh hae ah ae ra eer ey, |S ate RR a ete ae Sof aie cio eroe lea cral tence latee] esate eelee | eet Del RAE | ie aH PP. ee | eee Nate omnia Ae tana seis mssi[ omelet esis allie seers stars [torre eee UENS Oa eee see eee 24 peetetete tae Pe eee ae acme nine we sto seis cece ce eel asm ance scammers of seallne Secale Wgeeoe ize ERASE ae eee pee lommate-lostass— ons) e:- Epa Eee eel keeaeaee| (re es oe eee ees Ip ee SLE oval; sharp anteriorly, rounded posteri- orly. sees |ecoceolbceid ecetbodeacas| |scorsoscscue py |seae [aoe PE esa ey [Ea ge (Sa eget Mappers | rete YL B27 SORE] ae BEC SAP EE eee eee eens [ae Sel cpl | ere ee A Cr kak All 2 fat eee 27 2s a .---| Regularly Sito 5rt2 tole aes MOU swese eee lan nes Soe em eke 4| 28 ovoid. 3. truded by io | dine only. we |e al os eee ea On AN a ee Bs Ea ah bay Gas) Ohm IL pees Rea Oh arGlesnce Suipleby pees eee le Presontille sole coal ece-c ellscaecat Cuaro-| tee. to mato- 2°0 hile od- jes 4, ESRI SA orl NS aes Shc eee NS Pisa oN Grey le | al sk Sa (Re pee, st lil J bese Baceen| Sees Ovoid..... FRG BARA Pes Bees] Sec ce Seen Beee Bere hecsee clea 30 144 REPORT OF THE COMMISSIONER OF FISH AND FISHERIES. Tabular key—Continued. pene ese 2 2 er ta EN ee CE ee Myxosporidium. Cyst. a Fi = isee ay is = Host. ov -— ~ we Size ws as Size oo FI g : Nuclei. re cS iin Sti Shape. | Color. : g| s ae A fs | 3 Be ee) is 2 2 3 S Se hie = By es a ca as Z Sale Bl eee) toe a a | & a Ay oe Ta See elete eos anche ||Aacecsee |---seee- POTLOM tetas eemiaae (SS Sagau\(pan-de ae Leuciscus cephalus. 1G eae Meeeaedl Beets Beesae asl ASeosaa cee aces clean osa RES SAON tah FUR al hcp PA Leuciscus cephalus. Ga eral ee ell seeerotdl ce anaes |recin aah | tina cea ae Some pe ares Bier eer meee ieee Gobius fluviatilis. -- Ih f | ahaa: Be SAae peee | seepcaesc Gonscoodl Besse sre Sener sommes sane ces| eres ss ‘Crocodile?’ --2..a-=4 SAE ees ate tl eecce cll seeetios cline sees =eisoe seals tees IPRESeNG| jeeane as] =seee ea Chondrostoma na- sus. TD) Ae | OS cee A | ea | a er es hs [Ee a oo eo ee oe eee aaa ose Leucisens rutilus. -- OM Bee pees tase bet Moe alae Aa iollomicin seers {oa aas Cen hee eae maeee =a sean cee eee TinGantincga--- sees Dil | Se | eel 2 ees kee seer Spaces Se casea| enc beccteansedocone seseeoos Leuciscus ery- , throphthalmus. ODM pera ie Rae SORE (SRS EOE ES Stic corn cyanea liseece seas ee aes come are farses Gasteresteus acule- atus. , 228) eciae | beeoae So Secel Mees Gar See aoa as seein Melee small |Sesemeiee eaaaey-t Stizostedion luci- operca. B- GELS |. aad eee eee Mee le eee eras eel eet el Reeendl Ree ery IS SUM ori clSaacnca a Gasterosteus acule- , | atus. As |lSceatel EA Ss leosese| Heresies Seicdrerse BOSE) Se saco bance aaa cece soe Seasanc = Scomber scombrus. . . 26 |20to| x | Hair-| Very On) hpaacstee cl cane leesece sels an- mond meee eae Alcyonella fungosa- 200 like, |numer- nearly| ous. " always { local- ized. FTG mepeneny ta SPN eee ead a Mem= |) Maniy;.:|\. 2<- chic Sesice ction dace see cueee lan ed cases Cee eee | brane number not sub-| incon- persist-| stant. ent. 2 j\iaeewe i eseer(ereee ees Mem- | Many.-|.....- WEG) sseeeaadse odessa Callionymus lyra-.-. brane not sub- . persist- ent. UR ees Seek cee emeh menor x Miamy.-|zeesoe Pin- |Spheri-| White.| Gast. aculeatus, head to | cal or Pygosteus pungitius pea. | irregu- Aphya alba. lar. 1) 6 hs pees Pl ee Pa Moem->\'|"Man yi; ||v2222| $20 csc soe saee|o one acice|Sonsmoseoe beeen aeeee brane |/number subper-) incon- { sistent. | stant. 2) Neel Sete ae einton | siscine aie Sporo- | Many. |.....- ING we eeeeaasaoeacoseS Cottus scorpio...... phorous vesicle 15 to 18 win di- ameter. 1 i kee oe epee ere) ae ed bop Aa Mem: Sse) ean| Sociale cecine cael Decapoda -.....-...- . | brane |ber con-| ~ subper-| stant. |sistent. | BO) Sacee lseaweclesosts ieee eae | a2 BARRA Silscses INONG ss 2ceerecses ------| Astacus fluviatilis... THE MYXOSPORIDIA, OR PSOROSPERMS OF FISHES. 4 Seat. Tabular key—Continued, Pathologic effect. Remarks Body cavity Mucosa and muscn- laris of intestine. Roots of tongue - --- Heart; heart blood - Scales Subsquamous IBTANCHIe = 2s. 2c<=55 Branchial ‘‘copules” Subcutaneous Subcutaneous. Subcutaneous. Inter-fibrillar Striated muscles. ---. Striated muscles. -.. Fc 92 Death of poly- zoan colony. Degeneration of muscle fiber . No degenera- tion. Crayfish epid- emic ? 10 Kiel. Capsules not yet demonstrated. Diseased mass form- ing white streaks 5 or 6 by 3 mm. 145 Genus. Species. x) A mn oO aS) = Genus incert.--.| sp. incert -.-.---- 14 asi arb pacorice sp. incert .....-- 15 dO sa eeeue ees Splincertia- se 16 EO esp aosee ee Sp-uncert=.-<. = 17 Be Oi eetaae fer sp. incert -.-.---- 18 YO eesaes Soe sp. incert .----.- 19 RO é Se hcon te Sp. mcerbre--s-ee 20 sie Sesegoosce sp-incert:.-.-:-- 21 E f80) pSapoeoe soc Spsincerdls-4-—-- 22 (Uh mremooscos sp.ancert)--2---- 23 2-GU)-Sechcecdes Sp.ineert 2-2 -- 22) 24 eSiOE, Sansebcace sp. incert -..---- 25 “Myxospori- | bryozoides-.-..-.-. 26 dium.’’ (Glinnger er eS SS eC secacaqens cs I acti SeeceeiGae ae destruens -.-.-.-- 27 Be LOD ee aati | anomala -..-.-..- 28 Pleistophorgeon-|- << -c ence ==" IL pee Omar essesst.- |p by PiCalis teens 29 HERG LOM ATA) Sete |e elralo am aieinte sate Tit Sieecteatoes contejeani......| 30 146 REPORT OF THE COMMISSIONER OF FISH. AND FISHERIES. Tabular key—Continued. Spore. < Vacu- Capsules. Shell. ale Symmetry. 1 only 2 or more in— a j S. Altes = |2 separated ae on (= A. =s £2 =| groups. ue Genera. aa S os it | mt. S seo co Rope) Se eB | | 4 ; = "Ep eal by } Oo |oH! 8 Bo Mies Bivalve. | 7 & : 3 i A, ah ee =] => + © iD =z ° 2, \% = qh aa Cin at e (3) set @ ey EISZaTP a es | S03 Pe oley ale cove: || > 2 oo! &@ |~h | BF Ses a ein es : I 3 SSeS ae) | == Zen) ee | ja = | 2 Bas] & | o2 | ae ee|al@|¢ = 3 = ‘ icy =I eQ| os Ba |c = 4 o i= nN a /8 ° ASM SS Oe SS ite +2 2 2 38 b |\S | EI Als | 8 = 5 S = 4a] A qin| 4 aia ND 31 | Thelohania........ Oil ete arell Sera Seal Mee ere coe ators ae ci es ee see) OL Asche a tees See FP ileaaed Gass osoceres DC lise etalece ee (Gana eal a a eels HN Pe ee Be ie SS, | SES Oss eae shee aes Boel sate Olciseeiae cle se cael EAS TREN A: Cet ea eo: Sd Davee eed oe, Se Ieee ee Ae ees ee RR Ve aNiyxobolus'--55..2-\e25- x SF | eee) Le es x CONN ease 0| x with x few ex- | very ceptions.) gen- eager On eemeia ste care) | Ser D4 Peery mere Scrae Se ee ----| X% 0] Slightly im per- | fect. Gi came lero pe soecoe ace > paceial EasHes) Meeraey Neeasicce an sollisesee| Tee leita!) xO ti louaes Si) | Be aeiseAeeosso Soest ebelsea. Cis OS tates noes |b aeoeeace «aloe ate eacre| > sae) 0) | slic ntliy = see equal. imper- fect. Ht lara fee LO) rare epee toreie leer eral 2 eae eee eel Sere aac e cena cert Hemalteatela VO, xX Meese BSalbe ac) eseececcnsestel sceclse se (2)? Se ese CEE 2a eee ees Le Seo SX.) Aileeseee AON do ses ee ac ee tee | ebubeo (2) al 228 San teal SNES ae ea cll saa SAE ao) DC sl eae ZUG LONE a ee aes fatal ata PO Re (aaa | Pema | CRIES OPED aha Be ARTY) ame ee! Aa over soem SOR RINSED ers Or Lee ale ee Sen te Ne Bye fies ae Dees 41 2) x (Xx) BOE Ole elee eae eecn == Leet ech OK ee aR RNS ye See ce | Cel ee x 0 Xo) Sees RA eit) Sue oe a ells 2 cote | Soe are ee eae ae | eter eae le es Pe rr RS ee 71S RE Cops Seas Gam ad ciee| cae he Sane ee Ob toa aed Span iad Pe Boe Sh te a BG Ne bx. 0)a an welealse Bee DEE Ms eel leet ans 2) x OSiriiesaes hed D4 | x AM A. 200 es's cose cca sciia| teen ne ssloas.ot ol ae eee Come c ce eee eee paeeeee RS Sry pn Domo) orm 48 Nia tdo Week ets eal es ASN GQ)! Me aR | We PR PEO x) 0) Sees THE MYXOSPORIDIA, OR PSOROSPERMS OF FISHES. Tabular key—Continued. 147 Spore. ep 3 Index. 2 Tail. Dimensions. 2 ashe Present. a : & oo w |e : A e) 2 Single. 3 2 zs By A on 45 Hy ‘ 4 Outline on 2 * be el ue s g | vertical i) oy & | sa 8 2 a view. Shi a= Si ne s ats a| ad Fd ie Red ls= Sees : = aq a Q SS - oo g 2 A ) a n Ce oy roomed |S a By Bh se 2 : Tana RS: ae : Se fs - Pecan [fe 2 b= i =H ) 3 eat al ° i?) fo! ~ =| qo = cc Ree 9 a A > os + = a | 2 a 3 3 o A DS TN Si (i) = 3) 2 |'o | &0 = m | eo | @ = 2 \a}S |& g elai/ es) 2 Sah Sons smpie q |pia A 4 AlH|H my OO | ie A Orton obec ce ----! Pyriform - BO 2 ee Beeele one iep dian i( Ue el bos Beeces| Macese ease by ether only. 2 OEE Ee OES eee STA ef eee) epee Cn. 1) RL bs extruded only by HC! and HNO. Beat hed sarcic a's 252) Lea AHN, o| SopopboCo0es) pod eae Sos beescesese FalGHSe Sel deaccel|soocks xXeOnEX< <0 0 JeXSAI RBCS Be Oecoed — Soeee beers tt saa cae| Ss ceaces s a -a|c Sate ae cee |------|------ Sa eee) es een ase Ovates-<=-|52252555.-5-). Sha Beed Geer Peete nce BSA ees beamed priced SGacae oo ESET Renee comes Lanceo- aN Siro ha (C0) ees easel eles Se es oe qa SAestes (ec ataes |S ieee late-ovate. 8. een Perera le otetelle arate ss ace cic.atsic' als = 11 7 rle ss-dleacieaoece win areal tne lle oparekey o eleleeteral ei Pacalticesoc|e ee To anny ClO=| se cece l= Be SS Pere eon ahead Veryese |oseeee EEA eae late-ovate. ism’) 0 fo ees ye 885 BER COE COE Emenee none ie ert Aes Cee © en BT | Keer (epee | tues Ariel [stern ea (some- times X 2) cect telieno tec aee, Coe Boseppococon Tils= A Ae RCS coe | Ree AGG SerS eel ae seco| osonc Tash Bot OS Oc PS a (cad Ui Zo | ga J (some cular. times x") Hee S|ione Eoc see e .| Flatten ed- LONGowi27 |) S555) Gotan Alt) esate sacacl ee nore 3 ovoid. 0°50} Soe del SoS) See bese See seaanoee 18 (error?) | 12 Pe Bane Seo aeneced aaa Pees Seer eee cd sacsce (er-| ror?) 1 Se ci Gea | Re pate Tig So) Rae SI NE aE cl he oD AE ed | ARIE ee Tee | Koen Se eee a a en CUT eteyss ae aer | oe ial cian ae ee Seat Salle De SER lore os gpa ee oval. toler- ably thick. Gun leis/asheesera| ome 3 @yall 52-522 STERN UZ a | SPs |e | er eee di it es Re ae ee sp. 61. ee eee ees een aa com aiomee ca ass aaeieenacc| ons |ssccleaae | warts ceued = Ab't|.- sitosalestavaloacass 0°50 Species Ne. 39 40 41 42 43 tt 45 46 47 148 REPORT OF THE COMMISSIONER OF FISH AND FISHERIES. Size S = 2 | Species No. 39 48 Tabular key—Continued. Myxosporidium. Cyst. and endoplasm differentiated. Ectoplasm Pseudopodia. Nuclei. Pansporoblast producing spores ad plurimum. Pansporoblast. Vacuole. Size in mm. Shape. | Color. Host. sec- eee Very numer- ous. phorous phorous 12to ld. phorous elongate a mem- Sporo- Shi Peace. vesicle 10 in diame- ter. Sporo- Siem: vesicle spheri- eal, di- ameter Sporo- 8 vesicle fusi- form. Oval iu Desti- tute of brane? Palemon reetiros- tris. Palwmon serratus. Crangon vulgaris. Palemonetes vari- ans. Tinea tines,--oaccsne Misgurnus fossilis- Pimelodus clarias-.--. Tinca tinca......... Tincatinea-easekeers Mugil auratus..-.-.- Mugil capito Nais proboscidea. ... Lucius lucius-....... Gobio gobio........ Cyprinus carpio .... Alburnus alburnus. Cyprinus carpio .... Abramis brama..... Abramis brama..... Leuciscus cephalus. Barbus barbus..---- Phoxiuus phoxinus. Crenilabrus melops. Pseudoplatystoma fasciatum. Tinca tinca..... eae THE MYXOSPORIDIA, OR PSOROSPERMS OF FISHES. 149 Tabular key—Continued. Seat. eethoietg Remarks. Genus. Species. 3 a, Qa ovo cS) o ay n | Inter-fibrillar-.--.-- Mnrscular panes sess. sseceseceeeea cea Thelohania .-..-. | octospora..-.--. 31 sis. Inter-fibrillar. ee ee a ee ec oS Oe | Sl atiatescose eecmecacos S| 2-240) -seawecis see SARC iosseetce eae peste IMIS CIOS Some cece scceecriciss tacit clndeceaccueie sbeccuslnn: = ae dO eet os es aos macrocystis .-..| 33 TDOOO ASO Ge EC OSOIGOSO SEE CES E CRORES < ARE Cre: SASS er See INEVODOLUS | Heer see eetniacetsisalete/= re | vd ee me ey eta cae aecinecieisein sc aitie|lnaleremincawelstee code ays ----00...-...----| uNicapsulatus..| 34 PEMA C oS PLONE era leajsstocere site ee Sl maberetistaanacce seeteesles ae UO naceeaeee piriformis ------ 85 Kidney. | RNa oe aeidetore mat aeacicla |eaeboteiced caeeualecbedcocreaarad bogeed|senc8Wer sctenaace | AGEN seek cAl ae Mipleoney whe Gint okys | SSa eo ewe He ett eewiaae. atone saeeetce (Red O incase brachycystis....| 37 ¢branchia(see p213). ‘ COrmmedeaee nee see. |=- seeeceas, ssaans Were Shane ae oe seeta esl GO) hone See cai Spi ineerti= -2-2-0h as Branenialslamellssss|ceoc so ceaceewasllsccse cance wocesocesaee Ja -eO! teat castes mupilis -s--s---- 39 Branchial lamelle. Bere csedtors tensa ae Za. Loe sapbobe cdénca|peGeccar desosbescoascalhbs GIO sosedocpace)) sigh eke Gunceccene) Ah BTANCHUB = sse< 06 = 5-12 eps Mei ceravaee ema ss tlle okt iota) ara aicte tet ener Wee Ol =ckiedocowas sp. incert....--- 41 PRIMA ub naa Chi Der ee se ncacicene ea atosieeldc wat aunceraoneee eee dO aaeteses se) oviformis .....- 42 Branchiz. | Branchiz. amnion oa es ee ce escechccio Salcece Dimensions an er- |.--.do?........-.| ef. oviformis....| 43 ; ror? (see p. 215). BT AR CMID ae os soecl| Seasmeaes ee tems | miacewteSaclewciaseses [Seed Om saath cs ot: sp. incert ...-.-- 44 ISTHE IR Sap ae retin yy | ee eS ne jee cdOi seeaease ses sp. incert-...---- 45 era OMles mat sae ots als Sansecene! sctceelecesccho sis emeeeaaces Bs 2500) acess since<- milleri ..-....-- | 46 Branchiz and fins. Branchiz kidney. ‘Ovary. rantchialearehese es | hac os ose foo sce Sekine na aeteaee tesa S| POO So see tesae sp. incert.....--. 47 BEST WENA CHIU NO se satelite eats | teraiciaia in aiatatiaia a's afe||(s= a's sbinweiete eieiamtotetan alain Osc aeclateces bicostatus ...... 48 150 REPORT OF THE COMMISSIONER OF FISH AND FISHERIES. \ Tabular key—Continued. Spore. . Capsules. Shell. Vacuole. Symmetry. | 1 only 2 or more in— & | ie Ske = |2 separated ae 7 g \o A groups. ies! | 5 |e o ore { Salone Hi Ps Genera. Fee als a Bs |e oo F ; =| 80 iB Gsh=) B 2 5 3) R i 4 ay hl) nes ee Altec Bivalve. | 78 | ¢ a I Oo an HW = Land lam = ; a 1 ap Cs) Bo | 8 2S ‘5 . & a é a |Sa| + core aal ae .}s | 38 Q a . A Se iS @ | BF Solo iS 2 a a © 15-5 a > et ey : S “ny nD H Le i= >) ay Qa “4 ° ra } > 5 a [=] 22 Sim aa lr ° = 3 ° a) Oo |a ‘S) om) SS =| oO iI 2g = C5) 3 Be) | Gahran e s |al-3 | 8) 2 |e nD O\|5 =) dajlA BIN) ex A 1 ec ie + 5 = a Q A 5 GC) =| Fe A 3 a mL = B q |p|] & a = aye lala Sy aS) al d= ep eet Senos eeese cate eee eee Flattened-| 12 to 15 |9 to,.--.| 4 |------ 4) etn Pes ery ene 4 49 elJipsoid. aja! 0°33 x A eae iee tiles ois ts Resemb- 11 YP sllacba sper daeeoe | een al teers eas ae ected ae ae 50 ling sp. 92. | 3 x nl RS eee ea Lenticular 12 DO) tay eek ls" oll Ae sect eeeye Ms as AA SAY Been 51 or oval. A eetotel Sees slic ace fee ke ws a|eeesresaes Fee eal Go sricy Oe ake eee seed ee eed 2 SI a 52 an PN eter cyan |i Aileen) el ees ole S bee tl edhe om siata [otters aol Me Be alee Lael Se ara 53 aeolian al. ed 2 te 5 Spatular..| 14 to17 |8.5|5 to'4 or) X | 0°30 |...... About)....|? (see) 54 Ga) os 0°32. p. | 235) So NE SPN Pee ee al ee Broadly el- 13.9 Tale Sis foe mos See |= 5 eye Seri eae 4 55 liptie. SOU eames Sse Ao. Soh Broadly el- 14 1 0) ese ee eee UAC ib: |b semper 0.250 Recep aseae 56 liptie. tle less than 0°50. ON, GRE) SUE EROS Le SS ee ee [ea ese ee re es ere ea 57 aller bisejereiatni|isaies ces - Broadly 12 ata eee ae males =Fin=| ae slaaleetersays | mtctetats =entelineeoe 58 round-ellip- tic. mae ddl fee SENSI US a De, | (bee mi Eid ae | Fe at SS 59 nesce Pee eee oe Opherical - 9 So6E| Bees prise oo dcnl sesso loSeeee seers aoe shee cal CH me Ce eee sh a Sa Almost ex-!.--------- Be eer bee Soe tae Reo Meee peers JapellceSeeis 61- (see actly round, p. 240) 3% Aaa ee al ere Subcireu- 8 and) te Nae eeeo8s Aone (ERE eee iz 62 lar. le 0°60. EM ae alt swcinw sales oto Transverse-| 6 or7 See baleerel) oS SiPAbonel tae sl eeeces eae eye 63 , ly elliptic. “50. eee | eee teres es aests acl ences owals WES Sut Ua eee ee pope tetera ie [oe asa] Sm eee ors eters ear ree eee oe breadth. sue gll ste] tes al ae A AR RRR ten al Ue [ohh I plate Ue tea el ne Pees RRND Be LS ck he ck te eB he eel ee Rape ade, | eee gel a Pees SR a | Ae |) Si aas|ie cl CSeS SARE |S: eal (ee ee ee oe (ener: Fae fee Ne Sea Te | ae a Ne | ea ee ae S 67 apse S| eee 2 (na- Oval Pee MP EEN ge clo ea i Siig el OR a ere eb exit} ture??)| wider in ture front. 22). | | | x0 |X| X(sep-| x (sep-| Fusiform. |...-....-.|.---|---- 1) emer ess:|> 2.2.5 pial 7A) aie 69 aration | aration) to than of Gin] 5:9. in sp. |halves).|/halves). 80. | Omniiex 0 OMe ners: 15 HEtOlmecrloeaeeleasemaleeecee Hard-|os-325|seselseenes 70 | Cala} ly 0°50 | 152 REPORT OF THE COMMISSIONER OF FISH AND FISHERIES. Tabular key—Continued. size in ph. Ectoplasm and endoplasm differentiated. Species No. Pansporoblast producing spores ad plurimuin. Size in mm. Cyst. | Shape. Color. a © Myxosporidium. Nuclei. 5 % + 3 a ° a q (=) fo} z 5) A 7) cS Ay AY Large; Many. x and ob- tuse DES Ss ioe see x www wsele ee ee oes | ee ee eee rate ets lineata rete No panspo- roblast mem- brane. see eee Fespiroe times imino iat © Lond 5) 5 o a 5 Usually|------ 9 2, Present: 24-222. Pins i\eacsene5 head. Ad maax.| Round 1. or ellip- tic. None (!)..----. "Present. "0°25 to|...-.--- 0°33. 1:09 to} Flat 2°18. pus- tules. Admaa,\..------ 0°50. eee iam Peato | Oval. large nut. Host. Tinea tinca Leuciscus grisla- gine. o Ben aes Barbus barbus..-..-- Sree Leuciscus eryth- rophthalmus. Yellow-| Phoxinus phoxinus. ish white A White.| Erimyzon sucetta oblongus. soonesee Cyprinodon varie- gatus. sachaeee Carassius carassius. i arateleaee Alburnns alburnus. Betawe ts Leuciscus rutilus -. dehredeae “Gardoncseeaeees peewee Coregonus fera..-.-- White.| Stizostedion lucio- perca. apete Mercia Erimyzon sucetta oblongus. Saab Phoxinus fundu- loides. Bete Sane Merlucius merluci- us. BSsode Gobio gobio.....-.-- aa eae Perca fluviatilis .... wibtaceiaes Leuciscus rutslis..- White.| Coregonus fera -.--. Maes Tinca tinca-..-.---- ect ae Lucius lucius.------ bekwasee Stizostedion lucio- perca. sasncode Leuciscus eryth- rophthalmus. seen Lucius lucius...---- .| Gasterosteus acule- atus. Pygosteuspungitius. THE MYXOSPORIDIA, OR PSOROSPERMS OF FISHES. 153 Tabular key—Continued. Seat. ees ele Remarks. Genus. Species. 5 A nN BS & | Bram hyce anh lead GON, | ean ae ela emeit= a) |cinS eis\ctala'als nic'etaiale ini = Myxobolus -.--- ellipsoides....-. 49 liver, spleen, intes- tine, ?gall bladder (see p. 224.) eee ee ae as alan atars| sawncie geese sence |-----2cce--+---0-- ----|----dO ?......5.--| sp. incert .......| 50 Mnseles; (see also) ‘Barbell vepi- |2-----=--/--2-=-- ----2- See igescneacens sp. incert ..----- 51 pp. 227-228). demic. SPAGrAGEIGIAy Sesoed| pasassceoseocee™ | pedoc Gooceeosoe aoosee lesa (Oetaonnoecaos sp. incert ..---.- 52 WUTACe Oe NOAd enna. eenene sence soaite [aces vase ta ence enone Bae NP Se aee anes Sp. incert)-=:---- 53 Sprtaceomneadera. |p ase 5 cseees em (cae tnscgcste sods seces pedo eaewesestas oblongus -....--- 54 DIG CSOM DOWVEaseninial| Sas cis\slcieiscs seia1> Diseased mass fun- q---.do -.......... Lintonie sess. 55 goid, 4 by 2 to 10 by 4mm. LR GEN UNY oocdsao dl pssecaeeeue lode F osaeesoue Sopooe oscar) Saar GOr seb esse sp.incert ...--.-- 56 = og nnad QonoscomeconEss | ESossssecce eee ce Haeeacoo adore beccoous ss EBEH Oi pa 5ho Souda OCs Cseeososscall) Bx! MMMEMSUT ACG LOLOD. | aq—e hoa ocean |seaces eear tones snes. Psd Oech onos cycloides -.-.-.- 58 ercle, pseudo- branchiz. sp san toa pensS3505+ce5 Leche sSeaosbenon bled coeEccas sans seecse Bee sameness Sp: incert -<2---- 59 PsP OUT MAM COS Are | see See Ae Seno ae gece: sons eee neteectsc ae wesido slat awass: spheralis -.....- 60 perce, branchiz,; |:.:.<:.--------- Re Oe ovate see ere PESO! - cae ece sp. incert -.....-. 61 surface of head, fins. iprancmiallame are es acess het Panes? cee kee: seme seeee We dO ance soa globosus ....--- 62 DUDSgMAMOUS a2 (ea scce esse cds |ootinsiatehes ace ceesacses Lanes (ase eA Ae transovalis ..--. 63 Gallbladder soc mc \oe be cece asec Each - myxosporid- }..-.do ?.......--- merlucii.....-.. 64 jum produces only 2 spores. pRddney, body: cavity. --2.---25 2-2. =< [Signy fee eos Ses a Je Ei ah Peete sp. incert -.----- 65 LSI MICE MGS a ee ee ee Pe eee See LAE ad pga See ap. ineert):.2--<- 66 IG GES GE SEG LES. Ce ie a eae A Be em See es | 0 a ee a sp. incert------- 67 body. DHUEHEANCOUR MEAN |= Sane sates = os) j2ce5 5 elses es eeceemese BR AOT eA Coase zschokkei .-...-- 68 superficial inter- muscular tissue. COrmeaterese = pases tesa chescs 355356 \oie Se ceanap oe Ronee seme eed Omer a=. aes see sp.38...----- PS snc el cei ee ee ee eres, ace waye cock, we ode Sree Cees Ot eas ed 3 see sp.41..-.-.-- Operclessbranehiceralee ese Paste st west list 2 sone seco tes DSS E a Neael abe ee | see sp.61.--.---- Saiciniefesetas (olen = (alm = Sic es ee [eye 3 2 ote eee nal O beeatta ce ots SCONDEDA sermaia ee Owvarnyessoscccstiscin-' lactase seaascstie | b eit aves a aeeeenee eer JnnonG) Soceposose: ef. creplini - ----| 69 | | Renal. tubules and |.-......-.......- | 2ts ins <)aieinca cme oe reiae 2038) Geereenseod| SRA a Scorsen. 70 ovary. | Soni) SRS Saas 154 REPORT OF THE COMMISSIONER OF FISH AND FISHERIES, Spore. ( Tabular key—Continued, : ' s ‘ sts oso ‘ ‘ : Ha i : ' -_ ‘ on ‘ ' ' ‘ ' ' ‘ ‘ ' ‘roreyuroredng| $$ Sf xX ' ; mee : aera : ee : ; : meg vee) See a et : Apo } : : ; ie H ; ; t a : 5 Bees 0 i ; Ht : ; : E ' Pet aie ‘ : : ‘ 5 2s i : ; ' ‘ : ‘ : FI ‘Te1owpIg | & x ~ me x x < % x xX , | laa ; eal ‘ : aia, ‘ t ss yo ei ° 2 ry ry ° : ° rc) ° Src) ‘ co : ‘ : *1oT19}s0d-0.10,0W : : : : ‘ Ne ‘aqidourpoy | : i : x " x ; i Ke AG b exe i : : or . ‘ : : . . . . . . ‘ . . > ‘ortydourporay ‘ 4 i : ; i ‘ ‘ i eed ‘ tt ‘ : ; é ‘[eurpngsuoy 0} ound i , : ; ° ‘ ) ' ‘ cia Sp ‘ er ‘ ‘ ' = MoTJOUN[-VATVA JO WOLBULpPOUT ji ‘ ‘ : = ‘ = t : ree ‘ ae ' : ' NM ' ‘ ‘ ‘ ' . ‘ ‘ ' ‘ ‘ ' ' *OATB ALT : Xx : : x : Xx n : ree ot ‘ x ' : ; : H ‘ ‘ ‘ : Doe : ‘ i : i re ' ' ' ‘ ‘ t ‘ : ‘ ee F to ‘ : : i “SUT (9797 ‘ : ‘ : ‘ ' ie H an ‘ : : | | $4,| Pue gus) yovouy | | : : ‘ ‘ : ' : ‘ tae ce : Ft ‘ ‘ : Fo aI 5 ' , . . ' . , . ’ . ' . ttl . . ' 2 SE, “puo (dorroysod pus ‘ H ‘ ‘ ‘ ‘ : : ‘ ee ‘ eta ' : ‘ 3 5 ag IoL19}ue) yous yW ‘ ' ‘ ' ‘ ‘ ‘ ' : fee Sa ' noo ‘ ‘ ‘ ls nN So a a a a aa a aa ‘ : ‘ a : > > ‘ : : 3 a |*(pue coltojuv qv) dnois T | & : i : o : ‘ ‘ a ‘andvy APATITE ‘ ' a h a ; t t i i i 0 cea i i i | stes eaods !snonordsuop : H i : : : . ‘ : asa 3 ere ; 5 5 ° ‘ ‘ ‘ ‘ ‘ ‘ : ' ' 5 : t ' EO ‘ : : Ss ‘aynuru at0ds ! arnosqg ‘ ‘ ‘ ‘ ‘ t ' ‘ ' ie of ‘ ra) ‘ ' ‘ : ' ‘ ‘ ' : : ‘ ' : ' ‘ en ‘ : ‘ s ' : 0 ' ‘ : : ' : ieee ‘ thse : ‘ ‘ g pee eee ee Sy ee : A ae errs: : : : f-0] (=| ' ' ‘ ' ‘ ‘ ' . ‘ ' ' 1b ' ' ‘ [=| Lom ' ' ’ ’ . ' . . , ' ‘ ‘ ‘ ‘ ‘ oO S ‘ ' ‘ ‘ ' ' ' ' ' ' ' ' g ‘ ' . O 6 . . . ' . ‘ . . ' . . "6 ‘ . ‘ ° ° ° ° ° ° ° ° 2 ° os ° ° ° Be Rr aes eee ba s < oR en 5 3 z = ‘ ‘ ‘ ‘ ‘ ‘ : ‘ ‘ ‘ ‘ ue ‘ ‘ ‘ b= 6 : ! ; 5 i R : ae : nie) : 3 ‘ ‘ $ Ne) ON seedy | Ro Re 2 o = oO | Ss 4 x S . a q = re a 5 = ~~! “- J a « 2 . 3 |28| 5 > E Rea eu g as : ae ea RE i 3 See oes) Vom p ae Ia Sw PRieel oye 2 Stree |S ' (etme hs la gow 9] |o = &D Se chad et 3 BIW rea Sap | card ree Aas I ~ = A 3) = & ° = fs = |oO = ) 2 A S ° ® a | co) = a = T= = S <0 G34 Gea ite A Pa ee et ©) | Oa ae, eseaeebio Sa Pais | era | (asia Trans- 8 to 12 100 ae pr Uy emer ogee Be SC ee 87 versely subisos- ' celes-tri- angular. ; a | rere | oe eater enn ee meee aS tS ee oe Stace Se at creme SNES @ Sul PS cat ler as VI Paes ee as. olan Sub- Eco Baie ee east Hee Sera | Career Mer 365i a ea 88 spher ical. On Sener GSMS ees Trans- 6 8 |. 3 to x About}...--- peesi|e eee 89 versely 3°5. 0. 50. Ss elliptic. . Pa Das | Sete eee ella crate |larelwiaicle'a aie = 1GREE) ladaoecacel oe Sales [e-Aeeraaeaaell eee eeeeloace| ease 90 than breadth. XS ||secedllesossellbcaecatAcisocee S55 eesecqpec|secesocss 32 ASRS ISO CE ael aeood ocaliceoe Gene os 91 SE | ere imo Sts em terre Oval, 10 to12 Te Re 2 us Soe Se Sea el screens [Seem ects temeese 92 pointed anteri- orly. BOAO 5 ey See gen ae ae SSD LO Ste (ap Se ae aes ee Lr ne oN SN KE nS A A eS | rene Vali spherical. Sa RNR OA es LL eee CUTIE AbOH freee Salas mest cine ails tell sete ei eetere evecare |e eke cla terete | erect aye ara 93 ovate. Sed oe re Ds Solel Se eee Gunentionessecese le sete cea ee Jae es SA alee eee epee se nuets| All [EEL 94 ovate. oS ABSE| Merce. Omens Nearly BICONE | ia stole ase yer eee | ree se| Seem eae SES eal sedbee 95 spherical. Pon Sarinals iy spenoome SUDSPHEE=| LAMA. |. c0- seat see eee acme aoeeme tesco SE si Boro 96 ical, mu- cronate anteri- orly. eMac Soo st | voeae Tis) g 0 Aan eee eed SeRecer eG bec easel lccoantoc fecend Cece 69) Beate Bancoe vil BS lose peeaedl Eee ae Round- | 12to14! 9to10 |.-..]..-.. ARTO DN se ce sal sare ae XS Paecleonene 97 fusiform times length 159 ot spore 160 REPORT OF THE COMMISSIONER OF FISH AND FISHERIES. a = = Tabular key—Continued. Myxosporidium. Cyst. A 1) a me = os a BS ie Ee Host. co] = - Size | 3E Nuclei i _5ize | Shape. | Color inp.| §o “ S| ect otal leet inmmn. ' ; A s & Sse ° as 3 2 |22 a ge) & S eel 3 ae ee g je*| 8 g 3 2 a |8 3 a a a Ae Sn ee 87 | Spherical or oval; young stages amceboid, col- | None ..-....----------- Galeorhinus galeus orless, older yellowish; pseudopodia lobed, Galeus mustelus. motile; endoplasm riddled with spherules, 3 to 4, in diameter containing pigment gran- ules. NDE | Wee, seellbdedes) Banceods Bessinoos boShecc¢ dase Ssucnods sear omoc | asbncase | Be ens 50) ScbaansOSeLCoase cess = It costes Gostec|sepsccocs loorceer paeodaca 5 Se dlorcSaoee NOG! se sechea== a= —eeeee Gasterosteus acule- s atus. Pygosteus pun gi- tius. Phoxinus phoxi- nus. GE | peace) essere Socba son baceacsa) eSocsec-) (= ---|-0------ INGHGY sep apeossSScbseo2 Bufo lentiginosus... Uys Skea SSeeea loeeaceas | stacceed |acoseoas(c seq se ssceng|[Sanooes||Ssé0ese0 | aaeeete Acerina cernua...-- (tt leeesadl eee Soacseaslscooudod Seaorcce 19) | Section ee|enece acs | tee essere lascce mee Lotalota:------ese== | Oe | TIRANA Njg Pel Besos aga ymomacgs lecbosor a eeiec| aso c960q| Song 5551) [55 Scasee ese ce Leuciseus rutilvs, to rently | Leuciscus ery- 1500. | mem- throphtbalmus. |brane- t less VW | oo4S cc: Sessa |6SSaeeae Bacocoad sosussedse=<|Snedscecs INONO}e etek eee neon ele eee ee 2B 2D iy eerste see San|booeecds 1to4 | Bas sence Woner: .c2ss4-so-ee5- se. Raja batis -.>....... 88. 94 |29to| xX x Many x Uy ese ojssce INOnCssscenes===—==ee Galeus mustelus..-. 147. Seylliorhinus canic- ula. Scylliorhinus s tel- laris. © Pristiurus mela- nostomus. Squalus acanthias -. Squatina squatina.. Torpedo torpedo.-.. / Torpedo marmo- “rata. Raja clavata........ Dasyatis sp..-..---. Cephaleutherus aquila. ’ bal eae x Hetos |ias2es2=|soececes|o=--laseresee INONG 2 -caeceensnessass Leuciscus cephalus- \plasmic, lobed. OOM trader Meme ee sc -ece|cstowee =e Prob 2 \sesze es INONG sceee eveee wee emne Lota lota ....-.---.- | maa. brane ably. |(??) 75. | less VOU aa e535) Baa beedte lle seposel aS BEES Bee Beeenner Becreeee Seeeeeen Seeeraee Seeeeet rece ooo oo oe ooo. 97 | ad B4 Mese codecs ssheme) Bocticgne| sr Niner! NiOn6 pen scniewemeaceeeee Bufo agua.........- /man. ous Cystignathus ocella- 1500 to “vesi- tus. 2000. cles”’. THE MYXOSPORIDIA, OR PSOROSPERMS OF Seat. Free in gall bladder - Free in gall bladder. Renal tubules and ovary. Renal tubules and ovary. “ Accidentally’ in kidney. Renal tubules; urine and surface of bladder. Pseudobranchie --. Branchiallamelle. -. Free in gall bladder -| Free in gall bladder. Tabular key—Continued. Pathologic efiect. | Pressure ef- fects. Gall bladder Gall bladder. Gall bladder. Gall bladder. Gall bladder. Gall bladder. Gall bladder. Gall bladder. Gall bladder. Gall bladder. Gall bladder. Gall bladder Free in urinary bladder. Gall bladder ........ Gall bladder. F c——l1 Remarks. Myxosporidinm bi- sporogenetic. Posterior border of | spore radiate-toothed. | No ‘‘nucleus”’ seen .|....d FISHES. 161 Genus. Species. Ss 4 @ z Ceratomyxa soy spheerulosa.....| 87 Chlorompy Saw |Coewmcieote sees Wi (Spheerospora). sec) ssereeeaace elegans ...---.--- 88 GOss4-seecs ee | ohlmacheri ..--. 89 | Bel O) a coiateiain ses | perlatum -.--2-- 90 Olea cate sie Pepamcerbtes=ese 91 (lt pe scocecace dujardini _--<--- 92 ChioromiysuMmMe | else = See ae sieie tee | VI (sens. strict.) Seek OEE eae | iIncistm.--...-.% 93 ed Ore eee ileydieniesss scene) 94 MOV ssa fluviatile .-.--.- 35 SOO} ince 2s wyoeta mucronatum..-..| 96 (Gystodiseus,..-95|os- sc o>=e<- eee VIL OO sos ctu) immersus....... 97 162 REPORT OF THE COMMISSIONER OF FISH AND FISHERIES. Tabular key—Concluded. Spore. Vacu- ‘ Capsules. Shell. alas Symmetry. 1 only. 2 or more in— 8 =. * . = on é |S s 2 separated Bie 4 {2 4 groups. fale Genera. Sih eed os rete |! see ae Bs a eeie | 63s) @ ig P o\ak| 2 | Roe a Bivalve. | F 2 | ¢ 2 B 5 + Oo 2 H iS) S| | ial] Melon Sek = tp om | ta 2 eI &|2p/] 8 as et ° a 5 + I ‘ #/25)2| 22 | BE g2/2l2| 2 E Z, -~|55 ee oO net = 3° o| 48 ial = a © \5-n qe ~ a a 2, ‘ S ri n pe jae | & o 2 as Sea = 5 ° H } Co) sla 3 a2 OH I uo) a | H oO Pa a 5 |a ° So ao 2h Aa| 20) We S S o 3) | H im] 2 Q q|s =| a = oy 2\o oo) +a q A So) a 3 RD oye oe ee 4 A qin] 4 fQ nD GBaeC yiSTOGIS CTS ee aimee [epee ere ae mares AR are tetetetats X (valves | 90° |....|..-. 23 x x | each perpendicn- end. lar to trans- verse plane) VIII | Sphweromyxa -.|.... Seatae Pie Ne Sc Bced Mo [esses vO, 2 2 ? groups (posi tion ’) Beet Oia ea Socemeaace aera pect te el: Ke) eerie Oe alec PSA ea pees) pepaectoececoct each "ex trem- ity ” (end ??) exes | Vive diuim!s se. -|-= =. See lS Al yee x Wi |essesslbicise 0 Wi) Se \lbesetose ODE Beet Oboe weleisytatere| site Sens boos Bonners lor2 (WP |Keaees||Fa52 0 ON) Ca eerie in each wing Tih SS i Gy SSeS oaaelsore Fee|Gees) |oeace SOc 2, in ee Nedecchses 0 | But 1 plane of sym- 2 metry, viz; the groups valve-junction (posi- plane. tion?) LOZS eRe aCO) siscs scis sale == B Fas | Geral ee aseta se] OLD. Mallee emacs |foestes| aaesinese 2 Kea eee enone each wing. . , | —— a ae THE ‘ Tabular key—Concluded. MYXOSPORIDIA, OR PSOROSPERMS OF FISHES. 163 re. Sp Spo 3 4 ‘ Index.” 2 Tail. Dimensions. a 2 | Present. a S of ; |e Single aie is 5 {g. Bia = Lae Sila. ma A lod a Outline A) e ={lesl gs 5 - | on verti- % } alsa] §$ = 2 |cal view =| 8 Se g n . : =) Ss a c—] 2 ss o |8 A= n e 5 Pan ie q 3 \2 S .|8s| a i lenis eas Bt amily ee tees I = i) a n ° Rn he a } s = q S| aie |p : 2 3 ) Oo & A= | ry iS) >) a ta >) 3 A = = 3 2 a s Ser So ease Mh Ree B 5) ice = = s|2\le|4 Eo = | | 8 2(/s|Gie@ | a] ol) a © ° 5 tee (ee Bd) se sae = 5, q/pb \a4 AQ Hq =a) Sa} A OO} | & ia A R = ri S20 Se al ese Se ae Paranal ena weas ad\eeiisasscle ese t 1 moat nes Soetleceeee 98 sided fusiform. > (ecelbgenel Reese secre lone aihed | peace eee leteine wastes |e tee| ee Meleths dewie Be) [ete aes [eer ft ps VIL (? antero- | pos- teriorly). ; _ ones ee a eee Subfusi- |‘length”) ‘ width” Axis aE ...|4 (in- 99 form with} 13 to 16. of coil | elud sharply perpen- ing truncate dicular peri- extremi- to that cor- ties. of cap- nual.) sule. Ogee =... Sechelt as-ce| Sesspococd ee Sonses lasenponseue Sos| asuilinsereo eres Pee eget EO ee IX 0 ee ee ee Trans- 4to6 15 to 20 2to 3 eel tend noe 2 100 versely times unequally breadth biconvex of spore. lenticu- lar. 22 Salehese eae eae See p. 290. length(?) br’dth(?) Sos l2 x= |i a as\senalsacelaces | esccenil Lok 4tod. | 8ted. | truded by | HNO, 0 | aide | Seitinidc| ice ABS SGOORDOE Bebe soos Hoon Boonod= Db ass\a-a4|ScoSceer\Gaee hes Sessa) wlo2 164 REPORT OF THE COMMISSIONER OF FISH AND FISHERIES. Tabular key—Concluded. Myxosporidium. Cyst. | oo : . = ris B igs rd be F Ws 83 os Host. 3 HS Size | TS * aS Size in es apes 3 i Nuclei. 2 les mm, |52aPe- | Color. 2 g 3g tape als ° m2 mm z aa | 2 Bee i 3 < S Seal va 5) =) = 5 n 2 =) ry 2 ® A ola S) Q =) 7) 3 3 od MD 3) my Ay AY > ORs | Seectenesicees peoneers| (Seen cabs soeastec See eae ated prensa Tortrix viridana. - - DVO Pasar silieieiwiny chia aio Se win afm arm wlepece tad soso LS Speirs wm mre mlf teres whet eel eam re he eet ae Pale ate are to oe | OOM Sura |e Ge osee ee [oe = cee leceiase Le here 2am ee | i bey 6 Oe Sele ae Onus tricirratus .... Onus maculatus -.... TOL OV AE Sek eee eRe ence] acento [es Sk NM aaeceet INONG Corie sso chin niee'|¢ ciaaas ancien Sera ee 100 | ad xX (2kinds,|Numer-| xX DiImeon-.| INONG, .<25 es sceeseite=eee Lucius lucius......- max. obtuse | ous. stant as 300 by and fili- regards 136. form. pres- ence, position and mimber! LOls| Small ieee | do beds bets ee pee ee Nef salt BP or meee eaed i, pikes 3) an ee Onus tricirratus .-... some- | | Syngnathus #quo- times reus. bristly. Biennius pholis .... Callionymus lyra -. . Siphostoma acus...-. PO 2Mieeeee cle sec as| meee |= sso eee ese ces Salee Abaasel ascosdee lnGeseccd Beaossar Raja patis\ a steenees a ee THE MYXOSPORIDIA, OR PSOROSPERMS OF FISHES. 165 Tabular key—Concluded. Seat. eae Remarks. Genus. Species. } A nN Oo S 3 n ITSP GENCIRY Gononeed Beseccoscstsoone | Ceceoeocenesemcecerc Cystodiscus?? ..| diploxys-...-.-- 98 nc2 JAC CORC SESE BOOS089 BO DcnSSb0s Sesser ll he ocpeorce SSpeocm core Spheromyxa 25 -|-.2-4-5--5-05-=5--) WERE Geablahilad dere ae ant | om elaaiees mania || in etnoiss\w'eimigei=|sini-na'='s| r= - CPCS 85 SBeieic balbianii.--...... 99 Gall bladder. Excretory tract (se0 |.-..--e200.----- |----ee0----- -------- Myxidium...-.- Meio odosanaceses Ix p. 107). Urimary bladder... -}.-.-..-- 2.0.2... |-------coeee ons 0e- 2 -|a5-- GD) eSec08s850¢ lieberkiihnii....| 100 Se MlePIAG Cera socal scales dome cacews |acmaen osaceedaceects|eaes Gost. seecsas | incurvatum..... 101 Gall bladder. Gall bladder. Gall bladder. Gall bladder. Tene GING IS Aes oes ond Be Abecopccnctincay pcooccocooasrcboonedsose GOR Cano AGsHa sp. incert....... 102 166 REPORT OF THE COMMISSIONER OF FISH AND FISHERIES, NON-MYXOSPORIDIAN. 1. Psorospermia scizenz-umbre Robin, 1853.!_ Pl.1, figs. 1+. Hist. Nat. des Végét. Parasites, pp. 314-321, pl. 14, figs. 14, 15; pl. 15. Robin defined the species as follows: Cellule ovoidex vel raro spherice aut ovoideo-elongate; coriacee, intus granu- lose, achromatice, luteo-succinee vel luteo-fusce. Long., mm. 0-027; lat., mm. 0:018; spherice, mm. 0-017. In stratis (coloniw) indefinitis, vel cylindricis, fila- mentosis, circulatim flexuosis, continuis coherentes, raro isolate. Hab. Infra membranam mucosam cavi branchialis insitam in septo abdomino-bran- chio scizene-umbre. The species consists of three varieties. The description is Robin’s condensed and rearranged. VARIETY 1.—(Robin’s plate 15, figs. 2a, b; 4a, b; 6.) Microscopic.—Cells ovoid (27 by 18 ~) or spherical (diameter 17 »), a little flattened on one side, having an amber-yellow tint with a white shining reflex, strongly refringent, resembling fat drops; ovoid cells a little flattened with clearly defined borders and double contoured walls (1 » thick) rupturable by pressure, cell-contents then escaping. Con- tents clear, yellow, homogeneous, strongly refracting, liquid, in which float 5 to 8 or more, strongly refringent granules, 1»in diameter. Cells not altered by acetic acid or ammonia. Macroscopic.—Cells cohering into grayish yellow, flexuous cylinders (colonies) 0-5 mm. in diameter (plate 15, fig. 1); length sometimes 1 in. or more. Cylinders convoluted, circular, endless, usually united in pairs by a double or triple delicate transparent connective tissue sheath (fig. 2e, 7, g), the whole forming a delicate string rolled upon itself, in every direction (pl. 1, fig. la of this paper) into a flattened spherical, lobulated or nonlobulated mass, whose size varies from that of a nutlet to that of a fist. VARIETY 2.—(Robin’s plate 15, figs. 2c, d; 4c, d.) Microscopic.—Cells ovoid, white, colorless, transparent, with a shining reflex, with more numerous and larger granulations than the other varieties. Macroscopic.—Cells united into opaque, milk-white, filamentous, con- tinuous, endless cylinders, either by simple cohesion or by amorphous matter, which latter forms around each cylinder a (hardly perceptible) thin enveloping membrane (plate 14, figs. 2c, d; 4c, d). These fila- ments are only visible under a lens, being only +5 to $ as thick as the cylinders of the first variety. 1This species was first described as a constituent part of the body of the host by Robin, in his paper ‘‘Anatomie d@’un organe découvert sur l’ombre (Sciana wmbra) read to the Société philomatique Nov. 28, 1846 (Procés verb. d. la Soc. philomat. Paris, 1846, p. 140; also Journ. l’Institut No. 683, Feb. 3, 1847, Paris, XV, p. 41). Not seen; Jide Robin, 1853, p. 314. x : | THE MYXOSPORIDIA, OR PSOROSPERMS OF FISHES. 167 Variety 3.—(Robin’s plate 15, figs. 3; 5a, b; 8.) Microscopie.—Cells regularly or irregularly ovoid, alittle smaller than those of the first variety, brownish yellow, presenting a peculiarity found in no animat cell, viz, a round opercle.! Cells unaffected by acetic and nitric acids, and by ammonia. Macroscopic.—Colonies of variety 3, consisting of small lenticular, or irregular brown or white masses scattered here and there at the base of or below the lobes, and especially over the submucous surface of the parasitic convoluted-string mass. (1) Brownish masses.—2 to 4 mm. thick, composed of masses or colonies of irregular, cupped, operculate cells, the whole enveloped by a layer of cellular tissue containing very fine capillaries, Masses some- times sufficiently numerous to color quite an area of the mucosa black- ish brown. Further, when the convoluted-string mass is absent, brown bodies may occur in the same situation. These bodies are ordinarily accompanied by small pea-sized,whitish corpuscles, composed of round granules measuring about 0:20 mm., formed of strongly united fibers of cellular tissue wound around a small transparent, apparently calcareous, body. It contains in the center 1 to 8 or 12 cells, furnished with an opercle similar to that above described. (2) Whitish masses.—Composed of grains formed of 2, 3, 4, or 12 (rarely 1) cells, surrounded by a thick cellular tissue layer, the fibers of which are strongly united by amorphous finely granular matter, the whole forming rather hard, white, spherical or ovoid grains, § to 4 mm. in size, often clearer in the center. Calecareous granules forming an oval or circular mass (fig. 5) with sharply defined borders (the latter sometimes split); granules forming whitish, more or less flattened, friable, irregularly lobulated, pea-sized miliary masses. Granular mass destitute of vascularity, the vessels being confined to the tissue sheath. Some masses are hard, yellowish white, of variable form, composed of operculate cells, calcareous granules, and a great number of very large, quadrilateral or rhomboidal, tabular crystals, the latter often piled up,insoluble in acetic acid,in which only the calcareous granules disengage some bulle of gas. Caleareous granules also occur without crystals, being in this case whiter and less yellowish. The convoluted string (cordon enroulé).—As described above, the cells of varieties 1 and 2 form continuous (endless) cylindrical filaments, those of variety 1 forming yellow filaments, those of variety 2 forming white filaments. The convoluted string is usually? formed of 6 of these 1Robin gives the size of the opercle as 0:06 mm., but as he says the cells are smaller than those of the first variety (whose length is 0:027 mm.) this must be an error, pos- sibly for 0:006 mm. 2Sometimes, however, only 2 filaments (instead of 6) are present, viz, 1 large yellow filament (instead of 2), and 1 (not 4) thin white filathent. Also (very rarely) the convoluted string contains only 1 (instead of 6) white filament (variety 2) and 2 or 3 successive enveloping sheaths. 168 REPORT OF THE COMMISSIONER OF FISH AND FISHERIES. filaments (arranged in two series, a and b below) together with a con- nective tissue sheath (¢ below). (a) First series, composed of one yellow filament (variety 1) and two white filaments (variety 2), the latter applied one along each side of the yellow filament. One of the white cylinders is always flexuous, the other always straight and without undulations. (b) Second series, consisting, like the first, of a yellow filament (vari- ety 1) accompanied by two semitransparent, hyaline, whitish filaments, which resemble the previously described filaments in being continuous and endless, but which appear not to be composed of cells. They consist only of a thin wall filled with a semiliquid, finely granular substance. One of these whitish filaments is flexuous and undulating; the other, instead of being straight throughout its whole length, undulates a little from place to place. (c) Sheaths formed of connective tissue of the host, penetrated by delicate capillaries. Parasitic mass (as a whole).—Showing through the thin covering of transparent mucous membrane of branchial cavity as a grayish or whitish mass of convoluted strings (varieties 1 and 2), strewn with small brown masses (variety 3) of the size of a pea. Size of parasitic mass varying from that of a millet seed to that of a large goose egg. Some- times voluminous on one side and small on the other; sometimes com- posed of two or three separate lobes. Form inconstant, generally con- sisting of round or elongatedlobes. Arteries and veins few, extremely delicate; derived from vessels of neighboring muscles, which, with the loose submucous tissue, form the only bond between the mass and the tissues of the host. Injection with mercury (of the connective tissue sheath, described above under variety 1) demonstrates that the mass consists of closed lobules. When filled with mercury, no escape of the metal occurs unless greater pressure produces rupture. When very small, the mass may be unrolled and shown to consist of a convoluted string. Habitat, ete—Submucous connective tissue of branchio-abdominal septum (between scapular and last branchial arch) of Sciena umbra. Among 9 fish (male and female) examined in September, it was absent in 4. The size of the 5 hosts varied from 1:30 m. to 1:70 m. Sometimes, but rarely, variety 3 exists alone, the usual condition, however, being that varieties 1 and 2 are present together and are accompanied by small colonies of variety 3. Nature.—Robin regards it as referable to the Diatoms. Lieberkiihn! says that: The psorosperms of some marine fishes recently described by Robin behave in every respect like Trematode eggs. Whatever other view be taken of its affinities, this species is cer- tainly not myxosporidian. As remarked above (p. 72), the generic name must follow the type species. 1 Miiller’s Archiv., 1854, pp. 10-11. / THE MYXOSPORIDIA, OR PSOROSPERMS OF FISHES. 169 2. Lithocystis schneideri Giard, 1876. Pl. 2, figs. 1, 2. Sur une nouvelle espece de psorospermie (Lithocystis schneideri) parasite de VY Echinocardium cordatum; Compt. Rend. Acad. Sci. Paris, 1876, LXXXxII, pp. 1208-1210; transl. Aun. Mag. Nat. Hist., London, 1876, Xv, pp. 192-194; also see Biitschli, Bronn’s Thier-Reich, 1, pp. 590, 602; figured in Schneider’s Tablettes Zoologiques (fide Pfeiffer, Die Protozoen als Krank- heitserreger, p. 49); ib. Perrier, 1893, Traité de Zool., p. 459. Cyst unknown. Plasmodium.—Forming shining black (pigmented) irregular masses. Size varying from that of a point to 10 mm. by 4 or 5 mm., aspect and consistence similar to that of the myxomycete plasmodia; surface of mass showing hyaline cysts with a structureless membrane, 2 mm. or less in diameter, containing one or more, rarely several, white points (crystal masses) and spores, the latter arranged in an irregular sphere. Spores situated at the extremities of filaments, which radiate from a central point, at which is a nucleus of a yellowish substance. Hach spore is sustained by 2 filaments tangential to the extremities of its shorter axis. Wherever possible (principally in the larger cysts), the spores become, at maturity, so rearranged as to form a number of little groups; spores cohering by their previous peripherally-placed portions.' At the same time the two filaments become applied to each other so as to form a single tail like filament 3 or 4 times the length of the spore. The little groups then resemble colonies of Flagellata, but the tail-like filament remains motionless. The coherence of the spores is due to a secretion produced at the adhering ends of the spores. Crystals insoluble in acetic acid, soluble in nitric acid, broken up at maturity of cyst, forming a sort of network, which seems to function somewhat similarly to the capillitium of the Myxomycetes in the dissemi- nation of the spores. Pigment of plasmodium believed to be derived from host. The amcebze present in the fluid of the body cavity of the host are regarded as originating from the falciform corpuscles, which are seen to slowly lose their form, and Giard believes them to produce by their union and growth the plasmodia. Spores.—F usiform, length 6 to 10 y, breadth 1 to 2 4. Some cysts (apparently the smaller) produce microspores, others megaspores, both of which classes differ from the ordinary variety of spore mainly in being more inflated towards the middle. Spore with 2 filaments (subse- quently becoming 1, as above described) tangential to the shorter axis. Contents of spores merely a granular protoplasm, or from 3 to 6 falci- form corpuscles in course of formation, arranged around a central resi- dual mass, which latter is finally reduced to 2 or 3 strongly refringent granules, and may disappear at maturity. Effects —The parasite causes the formation of small nodosifies on the inner surface of the test, which may enable us to recognize the presence of this parasite in fossil Hchinodermata. 1T, e., the portion corresponding to the ‘‘anterior pole” of a myxosporidian spore, 170 REPORT OF THE COMMISSIONER OF FISH AND FISHERIES. Habitat.—Body cavity of Hehinocardium cordatum (sea-urchin), par- ticularly against the test between the mouth and subanal plastron, and especially toward the conical point which terminates the plastron inferiorly; also frequently on the inner side of the actinal curvature of the intestine. Nature.—Giard says: I have found nothing resembling the Gregarines, and the whole of the facts observed lead me to approximate the parasite not to the lower animals, but to the lower plants (Myxomycetes and Chytridinew); on the other hand, the spores being identical with those described as arising in the cysts of the Gregarines, one may ask whether the relation of the Psorospermie to the Gregarines is not a relation of para- sitism rather than of genetic bonds. : Prof. Biitschli, the only other author who has (as far as I know) commented upon this form, says: - It may indeed be possible that an organism as yet unfortunately only briefly de- scribed by Giard, his so-called Lithocystis schneideri, occupies a sort of middle ground between Gregarines and Myxosporidia, since it combines the plasmodioid nature with the production of spores similar to the Myxosporidia, together with the development of sickle-shaped germs in these spores. Unfortunately, however, as said, Lithocystis has not yet been fully described, so that the decision is at present somewhat difficult. Prof. Lankester? places Lithocystis among the genera of the Mywxo- sporidia. Pteiffer® says that this species forms ‘a transition to a still unknown side.” Remarks.—First as to Giard’s upinion, which is entitled to especial weight as being derived directly from a study of the form itself, while Biitschli’s is here to a certain extent an opinion of an opinion. In Giard’s article I fail to find the slightest indication of a desire to approxi- mate Lithocystis to the Myxosporidia. True he calls it a ‘‘psorosperm,” but he uses this term in a very vague sense, its scope appearing to be at least equivalent to that of the term Sporozoa. Further he states that: The whole of the facts observed lead me to approximate the parasite not to the lower animals but to the lower plants (Myxomycetes and Chytridinee). Then he argues that since the spores of Lithocystis are identical with the spore-like contents of the gregarine cysts, perhaps the latter (which he also denominates “ psorosperms”) are not gregarine spores, but gregarine parasites. Prof. Biitschli, however, says that while its spores agree with those of the Gregarines in containing falciform germs, Lithocystis possesses in common with the Myxosporidia, a plasmodioid nature and the pro- duction of similar spores. 1Ks wiire sogar moglich, dass ein bis jetzt leider nur fliichtig yon Giard beschrieb- ner Organismus, seine sogenannte Lithocystis schneideri, eine Art Mittelstufe zwischen Gregariniden und Myxosporidien einnimmt, da er das plasmodienartige Wesen mit Erzeugung ihnlicher Sporen wie die Myxosporidien, sowie der Hervorbildung sichelf6rmiger Keime in diesen Sporen vereinigt. Leider ist jedoch, wie gesagt, die Lithocystis noch nicht eingehend beschrieben so dass ihre Beurtheilung bis jetzt etwas schwer fillt (Bronn’s Thier-Reich, 1882, 1, p. 602). 2Encycl. Britan., 1885, 9 ed., x1x, p. 855. 3Die Protozoen als Krankheitserreger, 1890, 1 ed., p. 49. : *) THE MYXOSPORIDIA, OR PSOROSPERMS OF FISHES. Fit However much (or little) this may prove as to the stability of body- form in the Gregarines, I can not see that it proves anything as regards the Myxosporidia. Further, I can not see any_resemblance between the spores of Lithocystis, which contains falciform germs and no capsules, and the capsulate myxosporidian spores. Perrier includes it among the Myxosporidia. Finally, the following excellent paper (seen and incorporated at the last moment) seems to settle the question beyond doubt, and serves to remove almost the last ‘‘ transition” form from the taxonomic doubtful list: L. Cuénot: Commensaux et parasites des Echinodermes; Rev. Biolog. Nord France, Lille, v, Oct. 1,1892; Lithocystis schneidert Giard, pp. 4-6, plate 1, figs. 1, 2. The following is an abstract: L. schneideri is a perfectly typical monocystid Gregarine; the gregarine stage probably occurs in the digestive tube, being rarely encountered in the body cavity, the Gregarine probably encysting soon after traversing the intestinal walls. In fact, cysts are encountered upon, but not attached to, the intestinal wall. In the body cavity the Gregarine was always found (whether accidentally or otherwise) in the midst of a mass of cysts. Gregarine ovoid, about 65 uw long, protoplasm very vacuo- late, inclosing a rather large number of clinorhombic crystals, which also occur in the cysts; a voluminous nucleus, with large nucleoli, is present. Masses of the spherical cysts, well described by Giard, occur of all dimensions (ad max. 1to 2mm.) in different regions of the body, especially on the intestine and on the oral surface. They inclose a considerable number of spores and a voluminous rest of segmentation riddled with the same crystals that occur in the Gregarine. Spores of variable dimensions (megaspores 24 44, microspores 12 jz), ovoid, distal end neatly truncate, proximal end rounded; spores limited by a unique refringent integument (endospore) situated at the extremities of small, very delicately walled tubes, which latter form a sort of more or less undulating epispore. Spores arranged, at least in the large cysts, in a number of small, radial groups, formed by the convergence of the tubes toa common center. Contents of young spores granular; of mature spores 8 falciform corpuscles (4 at each end), and acentral rest of segmentation. The falciform corpuscles are probably expelled on the death of the host, and other Echinocardiums naturally become infected by swallowing the sand containing them. Pigment identical with the products of dissimilation spread through the tissues of the host; if specially condensed around the cysts, it is as a result of the [increased tissue] expenditure necessitated by their considerable growth. The presence of small nodosities on the test could not be determined. The cysts, united into more or less voluminous masses, are surrounded by a con- siderable mass of black pigment and of amcboid cells, the latter very evidently Echinocardium amcebocytes accumulated around the foreign bodies. The latent life of the cysts is probably not very long, as there are frequently seen, apparently in process of degeneration, small ones inclosing only empty spores absolutely devoid of nuclei. As in all the other Monocystids studied, the Lithocystis spore has dissimilar poles, the one truncate, the other rounded and furnished with along tube. The structure of the cysts is appreciably different from all other kvwown Monocystids. 172 REPORT OF THE COMMISSIONER OF FISH AND FISHERIES. 3. Genus et sp.incert. Pl. 2, fig. 3. Parasite of Gadus callarias, Miiller & Retzius, 1842, Ueber parasitische Bild- ungen; 1. Ueber eine eigenthiimliche Rranthert der Schwimmblase beim Biondahe Gadus callarias, Miiller’s Archiv. , pp. 193-8, pl. 8, fig. 1; id. , Rayer, 1843, Rayer’s Archiv. de Méd. comp., I, pp. 284, 287-9, pl. 9, fig. 14; ib. , Ley- dig, 1851, Miiller’s Archiv., p. 22, mention only; psorosperms of G. callarias, Robin, 1853, Hist. Nat. Végét. Panes, pp. 291, 309, pl. 14, fig. 1; ? psoro- sperm of bladder of codfish, St. George, 1879, Ueber die Feinde der Fische, Cire. 3, Deutsch. Fisch-Verein, p. 178, and Rep. U. 8S. Fish®om. for 1878 (1880), v1, p. 510; Myxosporidian? Coccidian? Biitschli, 1882, Bronn’s Thier- Reich, 1, p. 591, footnote; psorosperm of Gadus merluccius (error)! Bal- biani, 1883, Journ. de Microgr., vu, pp. 145, 280; ib. (error),' Balbiani, 1884, Lé¢cons sur les Sporozoaires, p. 122; ? psorosperms of cod, v. d. Borne, 1886, Handb. d. Fischzucht u. Fischerei, p. 211.2 Adult unknown. Cyst.— Unknown. Pathologic formation consisting of a whitish-yel- low, pasty mass drawing out into threads of a greasy, dirty character, mostly diffluent (evidently less advanced), witha firmer portion surround- ing the softer, in quantity about 6 fluid ounces, odorless even after several days exposure to the air; microscopic examination showing it to consist of the below-described corpuscles with a small amount of granular matter, the whole imbedded in and held together by a mucoid sub- stance. Spore.—Best described by comparison to a ribless ventricose Navi- cula or to Agardh’s Frustula caffeaformis, elliptic, length pretty uni- formly 14 to 17 yw, consisting of two valves, the substance of which is Shown by complete decomposition upon ignition to be nonsiliceous; their carbon incinerates with difficulty; each valve of an elliptic outline with a convex outer and a concave inner surface, usually in contact with its fellow of the opposite side by the inwardly convex middle portion of its border, the borders of the valves diverging towards their ends; sometimes obliquely set so as to be in contact by one end only, sometimes in contact for their whole length, thus forming a lenticular corpuscle, along the median line of which the junction can be plainly traced; middle of valves cemented together by a mass occupying part of the body cavity; mass showing more or less plainly a number of large and small granules, and apparently destitute of a surrounding membrane. Development.—By far the largest number of the corpuscles are desti- tute of asurrounding membrane; some were, however, observed heaped 1 Prof. Balbianimisquotes the name of the host as ‘‘ the merluche, Gadus merluccius.” The context (he refers to the diseased air bladder) renders it evident that this is an error for G. callarias, and not (as might be expected) for G. merlangus. Inferentially from his language he regards the form as myxosporidian. Perugia (Boll. Scientif., Pavia, 1890, x11, p. 134) has followed Balbiani’s misquotation. 2“ With the cod [Gadus morrhua] and mackerel [Scomber scombrus] the develop- ment of large psorosperm-lumps with great emaciation and later ulceration is very well known, and not rarely there occurs in freshwater fishes, from the same cause, a great mortality.” THE MYXOSPORIDIA, OR PSOROSPERMS OF FISHES. 173 3 or 4 together into irregular clumps. Many such clumps had no sur- rounding membrane, but some showed such a membrane containing several corpuscles. The features of the latter bodies were plainly dis- cernible through the enveloping membrane. The corpuscles at this stage are unsSplit, the valves being united for their whole length, form- ing a lenticular corpuscle. Further, similar cysts were seen which showed no developed corpuscles, but only large granules. Finally, a number of separated valves may be seen. From these facts Miiller concludes that the corpuscles in question develop several in a cyst, are set free unsplit, subsequently the valves separate, at first partially, at last probably entirely, and then perhaps the cycle is repeated. Habitat.—Air bladder of Gadus morrhua (= callarias), cod. Nature.—Robin includes it among the “ psorosperms.” Dr. L. Wittmack ! refers to this as a “ psorosperm.” Concerning this form Prof. Biitschli? says: It appears to me quite questionable whether these psorospermiform corpuscles of the air bladder of Gadus callarias are to be referred to the Myxosporidia proper or to the Coccidia. Their structure appears to approximate itself rather to the latter; especially in the absence of the polar capsules so characteristic of the Myxosporidia. I can see no myxosporidian structure in it, and have, therefore, omitted it from the subclass. Effects —Mucous membrane of the air bladder red and swollen, infil- trated by the parasitic mass. Tail unusually thin and shrunken, the soft parts being markedly atrophied, the muscular tissue having dis- appeared. Further observation must determine the constaney and causality of relation between the two conditions. Such atrophy is apparently not rare in Gadus, as the fishermen at Bohuslin knew the disease and informed Miiller that it rendered the fish unfit for food. Miiller says that the difference between this form and the psoro- sperms of fresh-water fishes is as great as that between different genera of animals. Atrophy of tail of Merlangus merlangus.3 The following observation probably can not be better placed than as an appendix to the similar disease of G. morrhua just described. Among the Mediterranean fishes collected by Mr. Peters, Miiller and Retzius noted a Gadus merlangus affected with complete atrophy of the tail muscles, the tail being composed of nothing but skin and bone—not the slightest trace of muscular tissue remaining. .The junction of the nor- mal and atrophied tissue was abrupt and was situated at the root of thetail. Unfortunately, the air bladder had not been preserved. 1 Beitriige zur Fischerei-Statistik d. deutsch. Reichs, 1875, p. 191, footnote. 2 Bronn’s Thier-Reich, 1882, 1, p. 591, footnote. §Miiller and Retzius, 1842, Miiller’s Archiv., p. 198; see also p. 172. 174 REPORT OF THE COMMISSIONER OF FISH AND FISHERIES. 4. Genus et sp.incert. Pl. 4, fig. 1. Entozoan of Salmo fario, Vaientin, Ueber ein Entozoon im Blute von Salme fario, Miiller’s Archiv., 1841, pp. 435, 436, pl. 15, fig. 16; ib. Leydig, 1851, Miiller’s Archiv., pp. 11,12; ef. Davaine, Traité des Entozoaires, Paris, 1860, p. I. Ameboid stage.—tIn blood obtained by puncture of the abdominal aorta of Salmo fario (brown trout) Valentin found, besides the blood corpuscles, some dark globules similar to round pigment cells. They have a quick, tremulous motion, also a definitely locomotive one. Observed for some time, a clear “tail” comes into view, which later elongates; there thus becomes revealed an elongate animal with a rapid motion, mostly of rotation, effected by 1 to 3 variable processes of one side of the body. Anterior and posterior parts clear; middle portion containing numerous dark corpuscles, perhaps pigment particles which it had eaten. When rolled up into a bail it often had the appearance as though each club-shaped process of the body contained one of the globules (pl. 4, fig. le). No finer structure could be detected. Size 7:5 to 125 uw. Sometimes a round opening appeared to be present at the anterior end. The posterior end is somewhat striate. The variable processes always appear in the drawing as they would be seen in the microscope on the right side. Perhaps the club-shaped peduncles are to be reckoned as such. In drawn blood they remain living from 6 to 8 hours. Nature.—These bodies are, Valentin says, probably referable to Pro- teus or to Ameba, of which they certainly form a new species, different from all of Ehrenberg’s. Doubting at first whether these organisms really belonged to the blood, Vaientin investigated the whole fish. He failed to find, either on the peritoneum, or in the kidneys, intestines, air bladder, brain, ete., any trace of these infusorial Entozoa. Only in the fourth ventricle (the favorite seat of the microscopic intestinal worms) did he find a single specimen. On the contrary, they were so numerous in the blood that often a single droplet contained 10 or more. The blood itself presented nothing worthy ofnote. The fishes examined showed numerous examples of Ascaris obtuso-caudata Zedér. No other intestinal worms were found. Leuckart! says: Still less is the gregarine nature of the entozoan found by Valentin in the blood of the trout to be mistaken. Lieberkiihn regarded it as an amceba. It could not, he says, be a Gregarine, as it lacks a nucleus.” Although this form has been referred to the Myxosporidia by Leydig, the evidence to sustain such reference is wanting, and at present its myxosporidian affinities can not be regarded as proven. 1 Archiv. f. physiol. Heilkde, 1852, x1, p. 431. 2Muller’s Archiv., 1854, pp. 11,12. For Lieberkiihn’s subsequent change of view as to the necessity of the presence of a nucleus in the Gregarines, see pp. 95, 96, \ THE MYXOSPORIDIA, OR PSOROSPERMS OF FISHES. £5 5. Balbiania rileyi Stiles, 1893. Pl. 3, figs. 1-5. (Psorosperms of mallard duck, Leidy, 1875, Proc. Acad. Nat. Sci. Phila., xxvi, p. 125). Balbiania rileyi, Bull. 3, Bur. An. Ind., Dept. Agric., pp. 80-84, pl. 2, figs. 1-5. Dr. Leidy’s description may be summarized as follows: Cyst, oval, white, 2 to 4 mm. long, 0°7 mm. thick. Contents, myriads of fusiform corpuscles. Spores fusiform corpuscles resembling minute navicellw; length 17y; habitat, encysted in interstices of muscles of the mallard duck (Anas boschas L.). Nature.—Leidy says that— Similar bodies were first discovered by the late Prof. Miiller and described by him under the name of psorosperms. They have been repeatedly observed since by Retzius, Robin, and others, in the muscles and other parts of fishes, and they are usually regarded as vegetable parasites. Though the mallard is not a fish-eater, the bird may have become infected by eating infected fish. From this extract it might not unnaturally be supposed that in this instance “ psorosperm” referred to a myxosporidian. Recently Dr. C. W. Stiles has reéxamined the subject. He studied material from two hosts and five localities, including one lot labeled: Oval, smooth bodies, no limbs. In muscles of Mallard. Anas boschas. Dr. E. Coues. Ex. Jan. 29, 1890. The following is the diagnosis: Parasite 1 to 6 mm. long by 0-48 mm. broad; rather fusiform, ends not sharply pointed. Cuticle not striated, about 2, thick. Central core not coloring and not containing falciform bodies. Peripheral zone as broad as central core (0-16 mm. to 0-16 mm.) or even broader, coloring in various liquids (acid carmine; methyl blue), containing numerous falciform bodies. Form of meshes irregular but elongated radially. Falciform bodies 12 to 14 long, more pointed at one extremity than at the other; containing a very distinct nucleus (21) which stains clearly in acid carmine or methyl blue, and which contains several chromato- phile granules; vacuole quite indistinct. Habitat.—Intermuscular connective tissue of ducks, the shoveler or shovelbill duck or spoonbill duck (Spatula clypeata), and the mallard or tame duck (Anas boschas). Development unknown. North America. (?) Philadelphia, Pa. (Coues; Leidy); St. Louis, Mo. (Riley); Clear Lake, Cal. (Brett); Minnesota (Liiger); Quebee (Bélanger). Type material deposited in the U.S. National Museum, in the Bureau of Animal Industry, and in collection of Stiles, Washington, D. C. Specimens are also to be found in the Army Medical Museum, Wash- ington, D. C., and in collection of Leidy, University of Pennsylvania, Philadelphia, Pa. In conclusion, although “measly duck” is not very appetizing in appearance, there are no grounds for believing that it is dangerous to man, 176 REPORT OF THE COMMISSIONER OF FISH AND FISHERIES. 6. Genus et sp.incert. Pl. 4, figs. 2-8; pl. 5, figs. 1-11. Pilzsporen of Cyclops, Claus, 1863, Die freilebenden Copepoden, Leipzig, p, 87; Myxosporidia? of Cyclops, of Diapt. ceruleus and of Diapt. richardi, Schmeil, Beitriige z. Kenntn. d. freilebenden Copepoden Deutschlands, Ztschr. f. Naturwiss. Halle, 1891, Lxtv, pp. 19-21; Entoparasitische Schliuche der Cyclopiden Schewiakoff, Ueber einige ekto-, and ento- parasitische Protozoén der Cyclopiden, Bull. Soc. Imp. Nat. Moscow, 1893, pp. 2, 15-26, pl. 1, figs. 17-34. Claus says: The bodies formerly! designated by me ‘‘spores of fungi,” with which I have many times found the body-cavity of Cyclops entirely filled, I have unfortunately not been able to observe again in later times. From the earlier period, sufficient notes on these bodies unfortunately are lacking, so that I am compelled to leave undeter- mined their nature and their relation to Parhistophyton ovatum, so full of significance through the disease of the silk-worm. To his quotation of part of the above Schmeil (p. 21, footnote 1) adds: “<< The organisms observed by me are, however, certainly not spores of fungi” [italics his own]. Schmeil further says (abstract): I have observed another parasite in nearly all the Cyclops of the Halle [Page 19] region, further in the specimens seen of Diapt. cwruleus Fisch. and D. richardi Schmeil. As this parasite is relatively very frequent—though absolutely (stdéndig) [Page 20] rare—one soon learns to tell the affected animals with the naked eye by their striking gray color. Their movements are unaffected. Microscopic examination shows individual parts of thé body strikingly dark (in Cyclopids and D. richardi Schm., black; D. ceruleus Fisch., dark brown); often the whole thorax, the abdomen, and even the tail, the first antennw, and natatory feet are either entirely or partly filled by this dark mass. On closer examination this dark color is seen fo be due to an innumerable host of small fusiform or crescentie corpuscles, whose form (plainly perceived by pressure-rupture of the copepod shell) places them as psorosperni-like bodies. From Schmeil’s description and drawings, Biitschli considered them Myxosporidia. Size very variable; besides very small corpuscles, one meets with larger ones 3 or 4 times the smallest, but the sizes of all those occurring in the same individual are always nearly equal. These corpuscles appear to possess a firm membrane, immediately within which a clear zone is situated. No differentiation of contents could be observed. Water and glycerin do not alter the form. Origin of these corpuscles unknown; repeated attempts to infect [Page 21] healthy animals failed. Multiplication.by division seems proven by the occurrence of two or several corpuscles lying close together, often in con- tact lengthwise; often, however, with their blunt poles surrounded by a common membrane. Therefore,in case the explanation generally given is correct, a double division in the transverse and longitudinal axes appears to take place. On account of the lack of infected animals it is exceedingly difficult to reach safe conclusions concerning these conditions. Such was the state of the subject when Schewiakoff began his investi- ‘gations. The following are his results: This condition has been observed at all seasons, first on Cyclops strenuus Fisch. taken from under the ice of a pool (clay ditch near Schlettau). 'Place not stated; or whether published, THE MYXOSPORIDIA, OR PSOROSPERMS OF FISHES. 177 Tubes rather frequent in very many fresh-water copepods, the affected [Page 15] individuals being distinguishaBle at first glance from the healthy by their opacity, the places where the parasites lie appearing dark. If in great number, the Cyclops appear completely opaque, and, indeed, according to [Page 16] Schmeil (loe. cit., p. 20), may appear dark brown to black. Discoloration caused by larger or smaller tubes filled with pyriform, spore-like cor- puseles; tubes occurring in body-cavity, and various other places, as the thorax, abdomen, tail, natatory feet, and first antenne ; sometimes in so great numbers that no part of the body is free from them. Spores in some places not in tubes but free in body-cavity, then always found directly on the muscles. These parasites were probably those which Claus observed in copepods and regarded as spores of fungi; also extremely probably those noted by other obseryv- ers, in various crustacea, e. g., Henneguy in Palemon rectirostris and P. serratus, Henr.eyuy and Thélohan in Crangon vulgaris and Astacus fluviatilis, and Garbini in Palemonetes varians. However, it cannot with certainty be asserted that the parasites found in the last-mentioned crustaceans are identical with the Cyclops parasite, as to the short communications no figures! are added, and the authors in question were unable to follow the whole developmental history. Technique.—The affected Cyclops was isolated in a drop of water on the [Page 17] slide and covered with a cover glass provided with wax feet, fixed in posi- tion by careful pressure on the angles of the cover-glass, so that it remains quiet and can be conveniently observed even with a high power (apochr. 4mm.). Between the observations the Cyclops was at first kept in a hanging drop in the moist chamber, but lived only a few (2-3) days, dying partly from starvation, partly from other unfavorable conditions. Consequently the Cyclops was next kept in a watch-glass of water, thus securing necessary food supply. Thus kept, it lived 14 days, allowing the development of the parasites to be followed. Several individuals were kept simultaneously and examined 2 to 4 times a day. Investigation of dead or crushed specimens is not to be recommended, as great bacte- rial development soon disturbs the study. For observation of the finer anatomical features and the developmental stages, the parasites were isolated by crushing the host and observed with very high powers (homog. immers. apochr. 2 mm., oc. 12 and 18). For fixation, picro-sulphuric, and chromo-aceto-osmic acids; for stains, alum carmine, hematoxylin; also methyl violet, safranin, and fuchsin. Examinations were made partly in water, partly in glycerin. 1. Amebiform stage.-—Met with in all parts of the body; most easily [Page 18] observed on the first antennae. Form ameboid-variable, globular or elongate; dimensions varying from 7u long by 34 broad, to 20u long by 6u broad. Plasma finely granular, capable of emitting on all sides blunt, lobulate, hyaline pseudopodia, always possessing a nucleus (pl. 4, fig. 2. N) and a small con- tractile vacuole (c. ve). Nucleus globular, showing the familiar vesicular structure, - that is, in its interior, a globular, homogeneous, more strongly refringent and more deeply staining nucleolus [Binnenkorper]. Contractile vacuole constantly situated near the border, in the end of the body which during progression is hindermost, pul- sating about once every 30 seconds; no food vacuole perceptible. This ameeba ordinarily creeps about over the epithelial and muscle cells and prob- ably feeds upon the same, as, although not directly observed, many epithelial cells were seen destroyed, and wpon them amb. After attaining a certain size the amcebx gradually cease their movements, draw in their pseudopodia, and encyst themselves. The ameebie may fuse to large plasmodes; several such fusions of 2 or 3 amb (pl. 4, fig. 8) were directly observed. Size of plasmodes varying with ‘size and 1The author is partly in error as regards the absence of figures. They will be found in the papers of Henneguy and Garbini, FC 12 178 REPORT OF THE COMMISSIONER OF FISH AND FISHERIES. number of constituent amcebz from 18u long by 8u broad to 48u long by 23 broad. In fusing the amcebe adhere closely to one another, finally after some time fusing into one mass, which can then undergo further movements. Nuclei (pl. 4, fig. 8 N) of plasmode vesicular, 2 to 3 according to the number of constituent amebe. Union or fusion of the nuclei not directly observed; regarded, however, as very probable, as frequently pretty large plasmodes of 22 and 184 (doubtless [Page 19] formed by fusion of 2 or 3 amb) were seen containing only 1 large, vesicular nucleus (pl. 5, fig. 2N). Besides, plasmodes seen to originate by fusion of 3 amcebe and to contain nuclei, showed on the next day only 1 large nucleus. Contractile vacuole not demonstrable with certainty in fusion plasmodes; its presence, however, not regarded as impossible; the plasma, on the contrary, con- tains so many vacuoles as to appear vacuolate or frothy. Motion of plasmodes rather slow. Plasma in the next 24 hours undergoing a change; the frothy, vacuo- late structure changing to a finely granular condition, the vacuoles vanishing. Nucleus, also, no longer visible; probably transformed by division into several globular strongly refringent bodies (pl. 5, fig. 3 N), though this was not directly observed. Motion of plasmode in this stage quite slow, ceasing entirely after some time; encystment following in 1 or 2 days. 2. Encystment.—The encystment of simple small amebze and the alterations in their body plasma is first described; afterward the process with the fusion plas- modes. Withthesmall amcebe encystment begins when they have attained a certain size. They gradually draw in their lobulate pseudopodia and acquire an irregular, more or less oval or pyriform shape. Locomotion still takes place, though very slowly, small ragged pseudopodia being still emitted. After about 1 hour this move- ment also ceases and the amceba revolves slowly, gradually rounding itself off and assuming with a state of rest a nearly globular form. After about 10 hours it has transformed itself into a proper cyst (pl. 4, fig. 3) about 10m in diameter, [Page 20] consisting of a plainly bordered, extremely thin membrane and finely granular contents, in which individual, small, strongly refringent gran- ules, a vesicular nucleus (N), and a contractile vacuole (c. v.), which now pulsates markedly more slowly, are perceptible. After about 24 hours (pl. 4, fig. 4) the membrane appears markedly thicker, double contoured, and the strongly refringent granules have increased in number. The nucleus no longer appears vesicalar, but homogeneous and rather strongly refringent. Contractile vacuole still always visible, although now pulsating extremely slowly (about once in 5 minutes). After another 24 hours (pl.4, fig.5)the protoplasm appears strongly brilliant, the contractile vacuole has vanished, and the nucleus is not perceptible. In their places are observed several round, strongly refringent structures (probably proceeding from division of the nucleus), differentiated from the other cyst-plasma granules already mentioned, by their more considerable size and their affinity for stains. Though the falling to pieces of the nucleus was not directly observed, the granules may with tolerable safety be admitted to have originated through nuclear division. Schewiakoff thinks that first the nucleus divides, and about 10 hours later the spores (pl. 4, fig. 6) are formed, since around every nucleus a portion of the protoplasm delimits itself from the remainder. Encystment of plasmodes occurs in the same way. Locomotion becomes con- tinually slower until finally it is extinguished. The plasmode then rounds itself off, acquires a somewhat elongate oval form, which, as also the size, varies greatly. It then secretes a thin membrane, which envelops it closely on every side (pl. 5, fig. 4). [Page 21] In 1 to 2 days the membrane becomes markedly thicker, then appearing homogeneous, strongly refringent and double contoured. During the next day spore formation begins. —_— THE MYXOSPORIDIA, OR PSOROSPERMS OF FISHES. 179 Plasmode encystment thus differs from that of simple amabz only in the fact - that the conditions observed in the ameba cyst (granular state of the protoplasm, vanishing of the nucleus, or, in other words, its peculiar falling to pieces into indi- vidual small nuclei) wear themselves off with the plasmodes during their motile stage. 3. Spore formation.—Beginning about 3 days after encystment; not originating through successive division of the nucleus and protoplasm, the nucleus falling to pieces into several small, strongly refringent corpuscles (pl. 4, fig. 5 N), around which, later, portions of protoplasm segregate themselves from the remainder. In this way the spores are formed. Thus in a simple ameeba cyst, 10 hours after the falling to pieces of the nucleus, 6 spores (pl. 4, fig. 6) were seen, each with a small globular nucleus. Besides these, the cyst still contained plasma in which were seen, along with many small, strongly refringent granules, isolated small, round nucleiform structures (N). About 24 hours later the number of spores had doubled; neverthe- less, there was still present undifferentiated plasma as well as nuclei. After 24 hours more the number of spores had so increased as to entirely fill the cyst; no free protoplasm remained (pl. 4, fig, 7). Spore formation in the plasmode cysts (also accurately followed) takes place in the same way. In plasmode cysts containing numerous small nuclei (very probably originating through successive divisions of the nucleus) are formed small bodies, globular to oval, delimited from the surrounding protoplasm by a delicate membrane (pl. 5, fig. 4), fine-grained, some allowing a small, globular nucleus to [Page 22] show through. After about 6 hours these bodies acquire a somewhat pyri- form shape, the membrane becomes thicker and sharper, the protoplasm more hyaline, the nucleus thus becoming more distinctly visible. This transformation proceeds so that after 24 to 36 hours the bodies are pyriform, sharply contoured, com- pletely hyaline spores (pl. 5, fig. 5), in which a globular nucleus is always plainly visible. Along with this transformation new spores are formed from the surrounding protoplasm, until all the free protoplasm is used up, the cysts transforming them- selves into spore cysts or spore tubes. Number of spores in cyst variable, dependent upon the size of the cyst, whose diameter varies from about 10j (simple amceba cysts) to 30 to 604 (plasmode cysts); often also elongate-oval spore tubes are found 70 long and 24 broad. . Spores: Length, 3:3 to 4u, oval or pyriform (pl. 5, fig. 8), rather strongly refrin- gent, completely hyaline, bounded exteriorly by an extremely thin homogeneous layer, the pellicula. In the broader end of the hody a globular, very strongly refringent, homogeneous nucleus (N), 1:64, is found. The spores thus originating still further increase through a somewhat oblique-running, transverse division, the nucleus dividing karyokinetically (pl. 5, fig. 10a-1). Division was followed intra vitam, and the study completed in specimens fixed with chromo-aceto-osmie acid and stained with hematoxylin. Nuclear division, requires about + hour, and pro- ceeds in about the same way as that of the micronucleus of the ciliated Infusoria. The membrane or external border-layer of the nucleus remains quiescent during the whole process, only in the last stages (pl. 5, fig. 10h) appearing some- [Page 23] what indistinct preliminary to reappearing with distinctness in the daughter nuclei. Owing to the small size of the nucleus, karyokinesis could be followed only in the principal steps. The first alteration observed in the nucleus is a marked increase in size; simultaneously it loses its homogencous character, acquiring a netted, honeycomb-like structure (pl. 5, fig 10a) with tolerably strongly staining granules. This netted form passes into an elongate, striate-fibered structure (b), the nucleus at the same time enlarging and assuming an ellipsoid form whose long axis coincides with that of the spore. Between the nuclear poles run meridional strix, in which the chromatin granules are imbedded. These latter become concentrated toward the equator, when a so-called nuclear plate (c) forms, which consists of baculiform 180 REPORT OF THE COMMISSIONER OF FISH AND FISHERIES. chromosomes which lie close to the delicate but perceptible threads of the achro- matic spindle. Regarding the spore from the posterior end (d), the chromosomes are seen to be 8, and to lie rather peripherally. After the formation of the nuclear plate, a halving of the chromosomes takes place in the equator (e), the halves reced- ing until they reach the poles of the nucleus (f). Meanwhile the spore has changed from pyriform to ellipsoidal, and the hyaline protoplasm has become by degrees granular. . Assoon as the chromosomes have reached the poles an annular constriction becomes visible at the equator of the spore as wellas of the nucleus (¢); between the daughter chromosomes, achromatic spindle fibers are very plainly observed. Soon at the equatorial constriction, an annular thickening of the spore membrane forms (h), running obliquely to the longitudinal axis, from above downward. In this stage the membrane (or external border) of the nucleus becomes indistinct and the fibers of the achromatic spindle also do not stand out sosharply. The annular constriction grows gradually inward and subsequently forms the partition wall dividing the 2 spore halves. Meanwhile the familiar after-formation of the chromosomes (7) takes place in the daughter nuclei, the nuclear membrane becomes again more distinct, and the achromatic fibers are scarcely visible. [Page 24] In the next stage (k) a distinct division wall between the 2 spore-halves is observed and the daughter nuclei show a finely reticular appearance, whence result later homogeneous nuclei (1). Division of the daughter spores soon takes place. A somewhat peculiar phenomenon was often observed. Among the many dividing spores some were encountered with their anterior (narrower) ends more or less inti- mately united (pl.5, fig. Lla-b). Schewiakoff could observe neither the union nor the division of the 2 spores. As, however, they differ essentially from the observed division stages, it may be questioned whether we have not here to do with a conjugation. This conjecture is strengthened by the presence, in the usually homo- geneous nucleus, of structures (pl. 5, fig. lla), which remind one of the nuclei of many conjugating Infusoria. The spores increase considerably in number, the spore cyst becoming ultimately entirely filled by them. After a couple of days the cyst bursts at one place (pl. 5, tig. 6) and the spores are scattered with considerable force around the body cavity. They then mostly lie (pl. 5, fig. 7) in great masses, or in groups of 3-5, on the muscles. As to the further fate of the spores nothing definite is known. After about 2 days they lose their homogeneous appearance and show an indication of a granular condi- tion. Four days later they possess an irregular form (pl. 5, fig. 9) with finely granu- ulated protoplasm and a distinct homogeneous nucleus. Size 3 to4u. Nomovement or transition into the amceboid stage (which transition is, however, regarded as very possible) could be demonstrated. The manner of infection also remains unexplained. Nature.—Without doubt Schewiakoff says, sporozoan. Schmeil, he says, considered it myxosporidian. (See above; the conjecture was Biitschli’s.) These parasites, especially the spores, have a great similarity to those found by Henneguy and Thélohan in some decapods and by them ranked with the Myxosporidia. Schewiakoff, however, doubts the myxosporidian nature of the Cyclops parasite. Henneguy and Thélohan gave their forms this place on account of their discovery of the filament. They only observed this extrusion a few times under the action of hydrochloric or nitric acid, and it was difficult to evoke. Since Schewiakoff could not discover either filament or capsule, he did not feel justified in referring the Cyclops parasite to the Myxosporidia. He, however, neglected to employ strong acids and alkalies, which is, he says, perhaps the reason of the failure. It appears tolerably certain that the Cyclops parasite is not identical with their Thelohaniaspecies, asthe latter havenoamesboid stage, the globular cysts (sporoblasts of H. & Th.) are of constant size (14), and have always 8 spores with a different structure, THE MYXOSPORIDIA, OR PSOROSPERMS OF FISHES. 181 The presence of a contractile vacuole in the adult, the peculiarities in the process of spore formation, the falling to pieces of the nucleus, the apparent absence of pansporoblasts, the occurrence of reproduction only at and as the end of the life cycle, and the further multiplication by the division of fully formed spores, all absolutely contraindicate any myxosporidian affinities. Further, the constant presence of pigment! corroborates this conclusion, which is still further enforced by negative evidence from the structure of the spore, the most prominent feature ot which is, of course, the absence of the capsule. Indeed it seems safe to go further and say that no organism with a contractile vacuole can, in the present state of our knowledge, be regarded as sporozoan (ef. Lan- kester, Encycl. Britan., 1885, 9 ed., x1x, p. 854). PROBABLY MYXOSPORIDIA. (Imperfectly described.) 7. Genus et sp. incert. Amecebiform corpuscles of gills of Cyprinus brama, Lieberkiihn, 1854, Miiller’s Archiv., pp.6, 7; ? ib. of heart-blood of same fish,? p. 14; ef. also Miiller, Miiller’s Archiv., 1841, pp. 491-2. Cyst.—Membrane so transparent that all details could beas well seen before as after expression of its contents. Contents ‘“psorosperms” and amcebiform corpuscles, or amoebiform corpuscles only. Myxosporidium.—Numerous, partly granular, partly granule-free, the latter usually smaller than the former, alterations of appearance very manifold, processes rather sharp than blunt, size not equal to that of a blood corpuscle of the fish; granules extremely small, held together by a mucoid substance. Spore.—Unknown. Habitat.—Eneysted in the gills of Abramis brama lL. (bream) in November. Remarks.—Its habitat suggests that this species is probably a Myxo- bolus. 8. Genus et sp. incert. Sarcode masses of Perca fluviatilis, Lieberkiihn, 1854, Miiller’s Archiv., p. 353. Cyst.—Apparently no true cyst (see mention below of membrane). Myxosporidium.—Consisting of granular protoplasm presenting a great similarity to that of Chloromyxum mucronatum, very variable in appearance, oval, lenticular or dendroidly branched. Size 27 to 440 wu (xo to $/"); some specimens surrounded by a structureless membrane, others not; sometimes the whole substance is seen to have fallen apart 1 While it is, of course, not contended that this alone would suffice to prove a species nonmyxosporidian, pigmentation, such as exists in the Cyclops cyst, would raise a strong presumption against its myxosporidian nature. ?Those [amcebiform corpuscles] of the heart blood of Cyprinus brama completely parallel in their form the above-described amcebiform masses found on the gills of the fish, and are differentiated among themselves in the same way as the gill forms [i.e., they are either granular or granule-free], Their movements are, on account of their small size, difficult to observe. 182 REPORT OF THE COMMISSIONER OF FISH AND FISHERIES. into globules (pansporoblasts) every one of which contains 2 spores or perhaps only faint indications of such. Spore.—Not described. Habitat.—On branchiz of Perca fluviatilis L. (yellow perch). 9. Genus et sp.incert. Pl. 6, fig. 1. Myxosporidium of Lota vulgaris, Lieberkiihn in Biitschli, 1882, Bronn’s Thier- Reich, 1, pl. 38, fig. 20. No description. Habitat.—Gall-bladder of Lota lota L. (=vulgaris), ling. 10. Genus et sp. incert. PI. 6, fig. 2. Myxosporidium of Lota vulgaris Lieberkiihn in Biitschli, 1882, Bronn’s Thier- Reich, I, pl. 38, fig. 24. No description. Habitat.—Branchie of Lota lota L. (=vulgaris), ling. 11. Genus incert. (‘‘Myxosporidium”) congri Perugia, 1891. Pl. 6, figs. 3-8. Myxosporidium congri Perugia, Boll. Scientif., Pavia, x111, pp. 24-5, figs. 15-20; ib., Thélohan, 1892, Bull. Soc. philomat. Paris, Iv, p. 166; Chloromyxum ?? congri, Gurley, 1893, Bull. U. S. Fish Com. for 1891, x1, p. 419; ib., Braun, 1894, Centralbl. f. Bakt. u. Parasitenkde, xv, p. 87. Myxosporidium.—Found attached to a calculus-like compact mass consisting of fungus (probably Penicillium), bacteria, and crystals. Individuals numerous, form variable, movements incessant, slow, ame- boid. Perugia observed in some a clear space which he believed to bea “vacuole” (pansporoblast), but careful examination failed to detect the spores. Habitat.—Gall-bladder of Leptocephalus conger (Conger vulgaris), eel, collected in August, 1890. The generic name Myxosporidium is not in good standing (see p. 206). In the absence of knowledge of the spores the generic reference of this form is entirely uncertain. 12. Genus et sp. incert. P1.7, figs. 1-3. Psorosperm of Notropis megalops, Linton, Bull. U. 8. Fish Com. for 1889 (1891), IX, pp. 359-61, pl. 120, figs. 1-3; ib. Braun, 1893, Centralbl. f. Bakt. u. Para- sitenkde, x11, p. 97. Cyst.—Globular, discrete or aggregated into clusters, white, with minute patches of black pigment from host; size varying from 2°5 mm. (single cysts) to 7 by 5 mm. (clusters); wall composed of connective tissue, thin, collapsing when punctured, indistinguishable from deeper layers of derma, staining deeply with ammonia-carmine. Contents, a milky fluid. Myxosporidium unknown. Spore.—Somewhat top-shaped, one end broadly rounded, slightly flat- tened, the other tapering to a point, length 17 uw; breadth 10 yu; thick- ness 6. Shell, thick and strong, resisting for a long time the action of sulphuric acid and of potassium hydrate solution; shape not changed by those reagents, by acetic acid or by glycerin, not staining with carmine; showing when viewed on edge an elevated ridge [junction of valves?], Capsules could not be detected. Protoplasmic contents appear in most cases to be finely granular. Tail absent. Se THE MYXOSPORIDIA, OR PSOROSPERMS OF FISHES. 183 Habitat.—Subcutaneous tissue of all regions of the body of Notropis megalops Raf. (red-finned minnow/ytaken in Black River, Lorain County, Ohio, 6 miles above Lake Erie, September 1, 1890 (also October 5, 1891; see below). Collector, Mr. L. M. McCormick. Identification by Dr. D. S. Jordan. With this species of fish were taken Noturus miurus, Catostomus teres, and Moxostoma macrolepidotum, and, in the immediate neighborhood, Ictalurus and Roceus. None of these, however, were affected. Effects —The epidermis of the fish is sometimes marked by dark purplish blotches. Scales are absent from the surface of the cyst in most cases, although a few were observed quite loosely attached to one of thelarger clusters. Allof the fishes appeared to be in fair condition. Mr. McCormick has kindly furnished me the following additional information: The fish were taken in the pool formed by Day’s Dam, near the center of Sheffield Township, Lorain County, Ohio. Although he has diligently explored the streams of Lorain County for material for his ‘‘ Descriptive List of the Fishes of Lorain Co nty, Ohio,” + he has never seen N. megalops infested by this parasite except in this very limited locality. The same day that specimens were first secured there he seined Black River thoroughly from Elyria to below Day’s Dam (distance 10 miles), but saw no other diseased specimens. Inspite of the admitted fallibility of negative results, | he believes this parasite to be restricted to a very narrow geographical range. Fish first taken September 1, 1890 (about a dozen); a few more October 5, 1891 (the first time of seining the pool that year). y 13. Genus et sp.incert. Pl. 7, fig. 4. Psorosperms of Gasterosteus aculeatus, Lieberkiihn, 1854, Muller’s Archiy., pp. 9-10, 22, 24, 354-7, pl. 2, fig. 28, pl. 14, figs. 9-12. The following observations by Lieberkiihn relate to a puzzling form found on Gasterosteus aculeatus (stickleback). His remarks are to me somewhat obscure, and I am not certain that I always understand his meaning. For that reason the translation is a literal one. [Page 9] Iam still in entire ignorance as to what becomes of the psorosperms of Gasterosteus. In the skin of this fish Gluge found cysts filled with entirely structureless granules which had a marked similarity to those of the Gregarines. Johannes Miiller has confirmed this discovery. Linvestigated about 100 cyst-bearing specimens selected from a corresponding number of healthy sticklebacks. Among 10 fishes there was, in the spring, about 1 available; in late autumn, on the con- trary, only 1 in about 100. The cysts varied greatly in size; the largest attract attention at once, the smaller are only to be discovered upon close examination. They have a very irregular form, mostly rod-shaped, and contain ordinarily the Structureless granules mentioned by Gluge. A few contained bodies with more defi- nite structure and characters, reminding one of the psorosperms, for which reason I willso name them. They are all nearly globular and somewhat smaller than the ordinary psorosperms; they consist of a transparent membrane, within which I have observed 3 kinds of contents, namely, in some a single small globule which is not large enough to come in contact with the membrane by its upper surface; in others lay, between the surrounding membrane and the upper surface of this [Page 10] small globule, a small mass of exceedingly fine granules; in still others the globule appeared to have divided, as 3 or 4 smaller globules were present. Several of the smaller cysts contained afar more finely granular mass than 1 Bull. 2, Oberlin College, Ohio, 184 REPORT OF THE COMMISSIONER OF FISH AND FISHERIES. that described by Gluge; I was not able to discover anything definite therein. So far I have found the largest cysts to contain only Gluge’s structureless granules. In any case these facts are not yet sufficient to establish a developmeutal series. In recapitulating and summarizing his results (the order of such summary and the place therein of the following extract showing that it refers to and is intended as the summary of the preceding quotation) Lieberkiihn says: In the skin of Gasterosteus occur, besides the grain-containing cysts discovered by Gluge, also such as contain psorosperms of peculiar species. In a subsequent article Lieberkiihn again discusses these problem- atical organisms. He says: [Page 354] As regards the psorosperm-like bodies of the stickleback, to which I have already, in my preceding =rticle, devoted some words, I have now succeeded in making the requisite observations preliminary to a knowledge of their developmental history. After I had, in the course of the preceding autumn and winter, examined in vain several thousand specimens of Gasterosteus for those cysts, | refound them first in March of this year in great numbers. Of the cysts discovered by Gluge Iam not at present able to give any explanation, other than that they are entirely different from the ones now to be discussed. Page 355] The latter I have frequently found, to the number of 30 or more, dis- tributed over the skin, the fins, and the cornea; some had bored through the fins and floated with both ends free in the water; others lay closely appressed to the skin for their whole length; others again were detached on one side. Individual fishes had their tail-ends so beset that scarcely anything of the scales could be seen. Their usual form is cylindrical; rarely they are ellipsoidal or spherical. They strike the eye with the first glance at the fish. The length of the rod-shaped is from ito 1 line; the greatest diameter of a cross-section about one-fifth line or more. The membrane of the cyst is plainly visible, and one can easily obtain it for exami- nation by removing it by means of aknife. I could not discover any structure in it. The contents present great variations. In some I found nothing but an albuminous substance, in which fat-like granules were suspended in great numbers; these were globular and measured 0:001’". If one moves them to and fro under the cover glass for some time many of them flow together to large oily drops. Other cysts contain partly these, partly much smaller but apparently similar granules. In still other cysts the granules of the smaller variety were united by a mucous substance into globules; many of these were distinguished by a much Jarger fatty granule lying in the middle between the smaller ones, and which often had an irregular form. In still others this was seen to be 2 or 3 times as large, and in these cases the small granules were usually entirely absent; furthermore, the whole psorosperm had a proportionately greater size. The diameter of such a body was 0:0038’’, of the nucleus [Kern] 0:005', of the fine granules about 0:0007'’.. In the largest, granules began to appear anew, and it sometimes seemed as though they separated them- selves from the nucleus. The expression nucleus has here no further significance than that which it receives through the investigation. Sometimes I was able to observe the same isolated, when for some unknown reason the surrounding mem- brane became ruptured and expressed its contents, It showed nothing but what one could see through the surrounding membrane. When the psorosperm dries on the cover glass it acquires an entirely different retrangibility, the sharp contour disappearing and not reappearing when water is added. In some cases I found also in fresh cysts such nuclei of feebler refrangibility within the smaller psorosperms. They vary greatly in size; were often simultaneously provided with granules, such being, however, often absent. In order to learn the further alterations of the cyst contents, I kept a number of cyst-bearing fish alive for some weeks in my room. Apparently the thin cysts increased in circumference, and then contained only the THE MYXOSPORIDIA, OR PSOROSPERMS OF FISHES. 185 largest kinds of psorosperms. Several fish lost their cyst contents entirely. In an apparently half-empty cyst microscopic investigation showed the following objects: 1. The largest form of the psorosperms, with a nucleus [Kern] of 0:005/’’ in diaineter and containing many of the smallest granules. 2. The largest form of the psorosperms, with a much smaller ‘ nucleus,” namely, of 0-003/’’ in diameter, and filled with a much larger number of the smallest granules. 3. Corpuscles of the same size with the same striking ‘‘nucleus,” with the same granules, but with a far less prominent surrounding membrane. 4. Corpuscles of the same kind, but without demonstrable membrane, slowly pro- jecting a part of the body substance and again withdrawing it, whence resulted marked changes of form. [Page 356] 5. Corpuscles with all these characters; also provided with such a “nucleus,” but with a diameter twice as great. In order to determine whether the structures described occur in the organism of fishes and migrate in the spring to the external skin for the purpose of [Page 357] reproduction, I examined a series of the individual parts of the fish. In the blood I found moving colorless corpuscies, which agreed not with those of the fish, but much more closely with those destitute of grains and nuelei, originating from the psorosperms. And I also discovered in the kidneys of Gasterosteus receptacles with tailed psorosperms and the various developmental stages of the same, just as they occur in the gills of the pike. As the cysts often beset the skin of the stickleback in such great numbers that their sub- stance ‘forms a not inconsiderable fraction of that of the whole fish, it would have been difficult for them to have escaped me in my frequent examinations had they been present within the body of the fish. HEverything speaks much more for the view that certain aquatic animals attach themselves in the spring to the skin of the stickleback, surround themselves with a cyst membrane, and in repro- duction fall apart into the psorospermiform bodies. It is this animal which con- sists of a mucous substance, and which contains many scattered fat-like granules, and measures as much as 1’ Jong and about }/ thick. The fat-like granules are employed in reproduction; they break up first into smaller parts and then form with a certain quantity of the structureless substance a globule which already con- stitutes the embryo of the new being. This grows gradually, one of the granules progressively increases in size and the remainder vanish. Growth then continues for a long time, until granules show themselves anew, which increase at the expense of the nucleus; the heretofore plainly visible surrounding membrane becomes appa- rently thinner or vanishes entirely, and thus a body is formed consisting of a mucous mass containing many small scattered granules and a nucleus [Kern] only a little larger, a body capable of motion and growth. 14. Genus et sp. incert. Psorosperms of Leuciscus dobula, Leydig, 1851, Miiller’s Archiv., p. 229. Oyst not mentioned. Myzxosporidium.—Two or three spores develop in each pansporoblast ( Tochterblase). Spore.—Untailed. Habitat.—On Leuciscus (Squalius) cephalus (=dobula). 15. Genus et sp.,incert. Spores of S@&valius cephalus, Schneider, 1875, Archiv. de Zool. Expér., Paris, Iv, pp. 548-9. Cyst and myxosporidium not mentioned. Spore.—Capsules 2, with very long filaments, extruded under action of glycerin. Habitat.—Air bladder of Leuciscus (Squalius) cephalus. 186 REPORT OF THE COMMISSIONER OF FISH AND FISHERIES. 16. Genus et sp. incert. Psorosperms of Gobius fluviatilis, Leydig, 1851, Miiller’s Archiv., p. 223, name only; ib. of Gobio [error] fluviatilis Ludwig, 1888, Jabresber. d. rhein. Fisch-Vereins, 1888, p. 30. Habitat.—Body cavity of Gobius fluviatilis L.' (goby). 17. Genus et sp, incert. Psorosperm of crocodile, Solger, 1877, Jahresber. schles. Gesellsch. f. Vaterl. Cultur, Liv, p. 45. Name only, with statement that it will be fully described elsewhere. Habitat.—m mucosa and muscularis of intestinal canal of “ croco- dile.” 18. Genus et sp, incert. Psorosperm of Chondrostoma nasus, Leydig, Miiller’s Archiv., 1851, p. 222. No description or figure. Habitat.—Cysts in roots of tongue of Chondrostoma nasus L. 19. Genus et sp. incert. Psorosperms of Leuciscus rutilus, Leydig, Miiller’s Archiv., 1851, pp. 222-3. No description or figure. Habitat.—White clumps of ‘‘psorosperms” in the heart (auriculo- ventricular valve) of Leuciscus rutilus; also in heart blood of samé fish. 20. Genus et sp. incert. Psorosperms of Cyprinus tinea, Lieberkiihn, 1854, Bull. Acad. Roy. Belg., xx1, pt. 2, p. 22. No description. Habitat.—Scales of Tinca tinea L. (tench). 21. Genus et sp. incert. Psorosperms of Cyprinus erythrophthalmus, Lieberkiihn, 1854, Bull. Acad. Roy. Belg., Xx, pt. 2, p. 22. Mention of occurrence only; no description. Habitat.—Subsquamous, on Leuciscus (Scardinius) erythrophthalmus. 22. Genus et sp. incert. Psorosperms of Gasterosteus aculeatus, Hensen,? in Wittmack, 1875, Beitriige z. Fischerei-Statistik d. deutsch. Reichs, p. 190. Mention only; no description. Habitat.-—On Gasterosteus aculeatus L. (stickleback) near Kiel. 23. Genus et sp. incert. Psorosperms of Lucioperca sandra, Heckel & Kner, 1858, Die Siisswasserfische der éstreichische Monarchie, Leipzig, p. 12; ib. Wittmack, 1875, Beitrige z. Fischerei-Statistik d. deutsch. Reichs, p. 190. Heckel and Kner say: Their gills are often beset with small cysts.filled with a gelatinous fluid (the so- called psorosperms) and in this condition they are regarded as unfit for food. 1'The great similarity of name between the present fish and Gobio fluviatilis, and the presence of a species upon the latter in the same situation (body cavity, see p. 243) suggests the possibility of an orthographic error. 2 In response to an inquiry, Dr. Wittmack kindly informed me that Prof. Hensen’s observation is unpublished, having been made upon a statistical question sheet. THE MYXOSPORIDIA, Ok PSOROSPERMS OF FISHES. 187 I am indebted to the kindness of Dr. Wittmack for this reference. Habitat.—Branchiz of Stizostedion lucioperca (pike perch). 24. Genus et sp. incert. Cyst of branchial ‘“‘copules” of Gasterosteus aculeatus Thélohan, 1890, Annal. de Microgr., 0, p. 203. No description. Effects.—Pressure on the heart caused death. Habitat.—Branchial “ copules” of Gasterosteus aculeatus (stickleback). 25. Genus et sp. incert. Psorosperms of mackerel, v. d. Borne, 1886, Handb. d. Fischzucht u. Fischerei, p. 211. No description (ef. p. 172). Habitat.—On Scomber scombrus (mackerel). 26. Gen. incert. (“‘Myxosporidium’”’) bryozoides Korotneff, 1892. Pls. 8, 9. Korotneft's | . a ae | bryozoides.| Date. Authority; reference. Jungosa. Myxospo- ridium*.| 1892 | Ztschr. f. wiss. Zool., LIIT, pp. 591-6, pl. 24. figs. 1-12. Do ....| 1892 | Henneguy & Thélohan, Annal. de Microgr., IV, p. 617. Dor. Sa: |v 1893 Braun, Centralbl. f. Bakt. u. Parasitenkde, XIII, p. 97. x 1893 | Ohlmacher, Journ. Amer. Med. Assoc., XX, p.562. x 1893 | Braun, Centralbl. f. Bakt. u. Parasitenkde, XIV, p. 739. Myxosporidium ? (development of).—For study of development, the polyzoan spermatoblasts offer a very rich material, comprising all stages of alterations. The earliest stage (pl. 9, fig. 1a) is a healthy, well- preserved cell, containing a large, round nucleus and, lying near it, the nucleus of the intruded myxosporidium, which latter is small, elongate- oval, dark-staining, and which, but for the complete series of changes exhibited by it, might be supposed to be a Nebenkern. The myxoplasm has, Korotneff inclines to believe, from the moment of its entrance so completely mixed with the polyzoan cytoplasm that we can no longer speak of a plasma differentiation. The nucleus divides by mitosis (pl. 9, fig.1b). Simultaneously or some- what later the polyzoan cell-nucleus divides, but this latter division is never by mitosis, and is rather to be regarded as an externally induced fragmentation. The nonvitaland artificial character of the cell-nucleus - division is further shown by the variable size of the nuclei, resulting from the division, the nucleus having lost the capability of growth. Its division results from an irritation of, or better, an impulse from, the presence of the intruded myxosporidium. This artificial stimulation of the powers of the infected cell constitutes the peculiarity in the action of the parasite which thus prepares for itself an artificial ground with- out which its existence would be impossible. Sometimes cell-nucleus division takes place somewhat later than that of the parasite, so that we already find the parasite with 4 daughter nuclei (1 of which was’ * Name not in good standing (see p. 206). 188 REPORT OF THE COMMISSIONER OF FISH AND FISHERIES. ‘ seen in way of further division), the cell-nucleus being as yet unaltered. With continually progressing division, both of the myxosporidium and the cell nuclei, and with progressive growth of the cell body, the origi nally simple cell metamorphoses itself into a plasmodium. Thus a young plasmodium was seen in which 1 of the 2 daughter nuclei 0% the host-cell had fallen apart into 2 granddaughter nuclei, while the myxosporidian nuclei had in the same time increased much more. In the next developmental steps of the plasmodium the number of the nuclei increases very rapidly, and with such increase their energy becomes ~ exhausted; the nucleoli vanish and the nuclear reticulum appears as a fine-grained granulation. Finally, the nuclear membrane shrinks and assumes an irregular contour. The cell nuclei then soon entirely vanish and we get a plasmode in which only myxosporidium nuclei are found With age the myxosporidia become displaced from the funicle and occupy the whole cavity. The zooid, thus become a myxosporidium- filled tube, closed at bothends. At this time the increasing mutual pres- sure produced by the continually growing myxosporidia results in their fusion to large plasmodes. Further growth produces rupture of the wall of the zooid and the myxosporidia come directly into contact with its chitinous investment. The morphological characters of the adult myxosporidium are here interpolated. Myxosporidium ? (structure of adult).— Naked, membraneless, amceboid- variable, size 20 to 200 4; form varying greatly with age, the youngest being globular, the older ones oval or lobulated from adaptation to external pressure-conditions. Ectoplasm perfectly transparent and hyaline. Nuelei very numerous, consisting of clear round vesicles showing in the fresh state round nucleoli. Applied against the out- side of (never within) each nucleolus is a small glittering globule. Pseudopodia formed by the ectoplasm, very fine, delicate and hair- like, ordinarily confined to a part and seldom covering the whole sur- face, often also forming small ramified tufts. Korotneff was unable to state whether the pseudopodia serve for attachment, but with the young myxosporidia the fixation to the funicle appeared really to oceur through these structures. Probably the direct influence of the water is injurious to them, and occasions a falling apart of the plasmodes and a freeing of the spores, which tien fill the spongy chitin-masses of the atrophied colony. In this state the spores remain the whole winter, and in April follows, prob- ably, the infection of the young Alcyonella (just out of the statoblast) by the amceba-brood from the spores. The time of the appearance of the myxosporidia corresponds with the development of the spermatoblasts, which ordinarily begins (around “Moscow) at the end of May, and the number of parasitic individuals increases pari passu with that of the spernatoblasts. While at the- THE MYXOSPORIDIA, OR PSOROSPERMS OF FISHES. 189 first their existence is appreciable by the microscope, soon (July) they are visible to the naked eye, the lower end of the zooid tube losing its transparency and becoming milk white. In August the alteration becomes very marked, the cavity of the zooid being distended and completely opaque. Spore formation.—How and whence do the spores originate? In any case their origin is endogenous (in the endoplasm) and probably occurs in the manner observed by Prof. Biitschli in Myaxidium lieberkiihnii, where a spore membrane is formed around a trinucleate globule. In our case are often found, in the plasmodium, nuclei in state of division. Around such nuclei, which are still united by the threads of the spindle, a resistant shell appears often to be present. Could this be a spore? Korotneff is able to confirm Biitschli’s observation that spore formation does not mark the end of the life cycle. In M. bryozoides, however, the spores always appear at a definite period of that cycle, viz, after the complete disappearance of the nuclei of the host-cell. Spore.—Elongate-oval, resembling a melon seed, sharp anteriorly, rounded off posteriorly. Shell extremely hard, very resistant, lustrous, apparently with an opening at the sharp (anterior) end; no bivalve structure demonstrable, though empty spores are not rare. Often, but not always, two vacuoles are visible. In the spring he was able to distinguish at the anterior end of the spore a glittering point whose signification was unknown. It might possibly be a capsule (nemato- cyst; Nesselkapsel). Habitat.—In very considerable numbers in the body cavity of Alcy- onella fungosa (a fresh-water polyzoan) in the neighborhood of Moscow, in the beginning of summer. The infection appears to be endemic, as Korotneff has never observed it in southern Russia and as it appears to be absent from western Europe. Seat and pathological anatomy.—Principally grouped around the funicle upon which the spermatoblasts (which serve as food for the young myxosporidia) are produced. No tissue except the spermato- blastsis attacked. Repeated careful investigations showed the absence of myxosporidia from the polyp and from the walls of the zocecium. Effects —The extensive infection exerts a direct (but only a mechan- ical) influence on the polyp, producing, as a result of its continued growth, a progressive atrophy, which, by the end of August, results in the complete disappearance of the polyp. The infection extends itself through the colonies, scarcely a single zooid escaping. The death of the colonies occurs much earlier than it would naturally under the influence of cold. _ RKemarks.—Henneguy and Thélohan believe the reference of this form to the Myxosporidia absolutely justified, although the capsule has not been demonstrated, 190 REPORT OF THE COMMISSIONER OF FISH AND FISHERIES. TRUE MYXOSPORIDIA. Ordo I. Cryptocystes Gurley, 1893. Etymology: «puyzroc, concealed, xvatic, capsule. Bull. U. S. Fish Com. for 1891, x1, p. 409; i6., Braun, 1894, Centralbl. f. Bakt. u. Parasitenkde, xv, p. 86. Myxosporidia in which the pansporoblast produces many (8 or more) spores; the latter minute; without distinct symmetry; with but a single capsule; type (and only) family Glugeide. Fam. GLUGEID Gurley, 1893. ( Glugeidées” Thélohan, 1892, Bull. Soc. philomat. Paris, Iv, pp. 173-4; Glu- geidea [Thél.] Braun, 1893, Centralbl. f. Bakt. u. Parasitenkde, XIv, p. 739). ee a Bull. U. S. Fish Com, for 1891, x1, p. 409; Glgeidz (error), Braun, 1894, Centralbl. f. Bakt. u. Parasitenkde, xv, p. 86. Definition (provisional as regards negative characters).—Cryptocystes destitute of a bivalve shell, with the capsule at the anterior extremity ; an aniodinophile vacuole; type genus Glugea. This family now includes Glugea, Pleistophora, and Thelohania. Before the proposition of Pleistophora, only 2 genera had been proposed. Their distinction was practically based upon 3 characters, a comparison of which indicated very strongly that either there were too many genera or too few. If, as Henneguy and Thélohan and the writer believe, these characters are competent to determine generic lines at all (in the opposite case cadit questio and everything reduces to Glugea), then the spore of Cottus scorpio should form the type of a new genus, for (see table below) of the 3 characters but 1 is common to it and Glugea, and, although 2 are common to it and Thelohania, the third (divergent) character is one of no slight importance in Thelohania, as it iscommon to all the 3 (probably 4) typical species. For this genus I have pro- posed the name Pleistophora. +s Pansporoblast Pansporoblast Myxosporidium. producing spores. membrane. Genus. SEES Nae = stalaloi ee Pe ee aeise See Isoneassere | Aa eer 1841 | Gluge, Anatom.-micros. Be ee Z. f aiigen. u. spec. Morphol., II, pl.5, fig. Se as aeetaers les acme ote Epps SaaS BaSdacme ss 1841 Millon Miiller’s Archiv., p. 491. Seeiiras ise x J SdeE Sages Gager Sose | sone syle) Creplin, Wiegm. Archiv. t. Naturgesch., 5 2 pp. 64-5. See aoe (Oe eel ee < Parst reece keh cest. 1843 | Miller, Rayer’ s Archiv. de Méd. comp.., I, | pp. 266-268. x< Sir ed Pee Sel Se Saeed eye cree ee 1843 | Rayer, Rayer’s Archiv. de Méd. comp., I, | pp. 266-70, pl. 9, figs. 11, 12. Cle eal nee cita tale [eave ainisions oll sree acoso! Nee ee ome 1854 | Lieberkiihn, Miiller’s Archiy., pp. 9-12. (See also p. 183.) Japenese |.---------|--.---+---| Nosemat|........-.] 1887 | Moniez, Compt. Rend. Acad. Sci. Paris, CLV, p. 1312. hep teenae| “Eesccctes x< SosHesseas| Mecsas! URE Hennegny, Mém. publiées Soc. philomat. Paris, 'Oceas. Centen. Fond., p. 170. Pease |netewevieneni- ieee sce csinne wo == 5) k889 | hélohan Compt. mend sAcad. Sei. Paris, CIX, p. 921, x x Seyaien | SBAGe ames |e. (Seeeoeae 1890 | Thélohan, Annal. de Microgr., II, pp. 202-4, 211-12, pl. 1, figs. 4,17. Rae els eat ieee s sors 3S |----.-----|....------] 1891 | Garbini, Rend. Real. Accad. Lincei Roma, VIL, Sem. 1, p. 153. See Wace oe tllne Mae LA |.---------| Glugea -| 1891 Thélohan, Compt. Rend. hebdom. Soc. g Biol. Paris, I1I, p. 29. eer ecey< ae|lte be ett Sarees, |---.------| Glugea .| 1891 | Compt. Rend. Acad. Sci. Paris, CXII, p. 170. eames = |----------|----------/.---------| Gluega, | 1891 | Thélohan, Journ. de Microgr., XV, p. 147. Ne) BeseSe |wwneeccece|-ncceeran=-|---05--=--| Glugea .| 1892 | Thélohan, Compt. Rend. hebdom. Soc. : Biol. Paris, LV, pp. 82-4. reece memaleiccaswcSee |~-eeeeee--|..--eeee--| Glugea -| 1892 | Thélohan, Bull. Soc. philomat. Paris, IV, | pp. 165, 174. Satie scenes Saas octal |.---------|---..-----| Glugea .| 1892 | Henneguy and Thélohan, Annal. de Mi- erogr., LV, pp, 619, 631, 633-6. 5 Bee ae eee |...-.-----|----------| Glugea -| 1893 | Brain, Centralbl. f. Bakt.u.Parasitenkde, | XIII, p. 96. Bee op | a= te ae at HE eyes Glugea .|.......---| 1893 | Gurley, Buli. U.S. Fish Com. for 1891, XI, p. 409. Sep odode Mea eee aoeo teaser onal eee ee Glugea -| 1893 | Braun, Centralbl.f. Bakt.u. Parasitenkde, XchV;, p. 739. Bees tote |S ciclo ncaa ||bcaeiscmersic | Glugea .|.....--..-| 1894 | Braun, ce ntralbl.f. Bakt. u.Parasitenkde, XV, p. 86. * The species is (fide Nenneguy, letter to author, 1893) Gobius albus. This identification was made by a ‘‘specialist.”” Dr. Gill informs me that the name Aphya alba should be used. t Nosema Nexgeli, 1857, was founded upon N. bombycis Newegeli, which was regarded as a Schizomycete (Tagebl. 33 Versamml. deutsche Naturf. u. Aerzte, im Bonn, 1857, p. 27). Cyst development.'—In a G. aculeatus kept under observation for nearly a year there existed at first a single cyst, quite regularly spheri- cal, attaining nearly the volume of a_pea. Very soon small secondary vesicles, at first scarcely distinct, appeared upon its surface, progress- ively enlarged and finally, instead of the primary cyst shelling out as a whole, it split open at the most prominent point and a great part of its contents escaped, leaving in place of the tumor an excavation irreg- ularly limited by a ridge formed by the non-empty part of the small sphere. The small secondary vesicles then developed rapidly and very soon formed an irregular strawberry-like mass. 1'Thélohan (Annal. de Microgr., 1890, 11, p. 204; Compt. Rend. hebdom. Soe. Biol. Paris, 1892, Iv, p. 82) also saw ae sts enlarge, become subcutaneous, shell out from their attachments into the water, and there burst. Rea / THE MYXOSPORIDIA, OR PSOROSPERMS OF FISHES. 193 i Cyst structure..—Number, 1 to 4 (sometimes a dozen, Thélohan), rarely ‘more, in contact or more or less widely separate; the majority as large as a small pea, some, however, attaining only the size of a pin’s head; size of tumor bearing no relation to that of the fish, being variable in the same individual; shape regularly spherical or only a little rounded; color usually whitish—when covered by the epidermis of the fish, _ silvery. Membrane always present, resistant, usually covered by the epidermis, which forms an outer cyst; surface granulated by alcohol; Contents consisting of a small quantity of a colorless fluid coagulable by alcohol, holding in suspension immense numbers of corpuscles which yield bubbles of gas (CO,?) with mineral acids. Miiller (1841, p. 491) found also some microscopic crystals. Thélohan (1890, p. 204) adds that the average thickness is 5 4; under high powers the membrane shows a fibrillary structure parallel to the surface of the cyst. Thélohan believes the membrane to be nonnucleated and considers this a strong argument in favor of its derivation from the similarly nonnucleated myxosporidian ectoplasin. | Myxosporidium.—Spore formation:? Myxoplasm containing small nucleated globules which surround themselves with a thin membrane, divide, and end by forming small spheres filled with very numerous rounded nucleated elements which later will yield the spores. Spore.—Very numerous, transparent, regularly ovoid, 5 to 5 y-long, 2 to 3 uw broad, size and form constant in spores from the larger cysts, less clear in those from the smaller. Shell bivalve; structure not demonstrable; chemical characters the same as those of other spores. Interior of spore showing a shaded portion at the smaller, and a clear portion filling the larger, extremity. Capsule 1, filament very long (50 4), extruded under the influence of iodine. No other reagent pro- duced such extrusion. The central (iodinophile) vacuole appears to be absent; a vacuole uncolorable by iodine is present, however, usually in the larger end, less frequently subcentral. Thélohan (1890, p. 212) has traced the division of the nuclei up to 4, a number which he has never seen (but which he does not wish to assert may not be) exceeded. Micro-chemistry.— Acetic acid produces no change. Sulphuric acid causes evolution of bubbles of gas (Co,?), the corpuscles at the same time becoming less clear but not dissolving. Potassium hydrate causes an agglomeration similar to the “rouleaux” of blood corpuscles (Gluge). The best stains for this species, Thélohan found to be gen- tian violet; but above all, safranin by the Gram-Bizzozero method. Habitat.—Subcutaneous cysts of Gasterosteus aculeatus (stickleback) in European rivers, occurring only once in every 20 or 30 fishes examined (Miiller). Subcutaneous cysts of Pygosteus pungitius (9-spined stickle- 1 Description Gluge’s unless otherwise stated. 2Thélohan’s observations on a myxosporidium in G. aculeatus (Journ. de Microgr., 1891, xv, p. 147). F c——l3 194 REPORT OF THE COMMISSIONER OF FISH AND FISHERIES. back. The forms habitant on these 2 fishes are identical, differing only a little in the size of the eysts (all fide Thélohan). Subcutaneous cysts of Aphya alba (= Gobius minutus and G. albus). In the last the deform- ity is even greater than in G. aculeatus. Nature.—Yor Gluge’s opinion, see p. 93. Effects —Even where the tumors occupy the internal surface of the opercle the fish did not appear to be hampered in its functions. Those which carry the tumors on the fins, nevertheless move the latter as freely and actively and execute all movements with the same facility as the sticklebacks not so affected. The tumors may be carefully removed without injuring the fish, which appears as well as ever after the opera- tion. Upon careful dissection, Gluge was unable to find any change in the intestine or in the blood. Thélohan (1890, p. 203) states that in certain cases the muscles are compressed and atrophied by pressure of the tumors, and the viscera are also compressed and no longer present their normal position or relations. II. PLEISTOPHORA Gurley, 1893. Etymology: wAevoroc, very many; gepev, to Carry. Bull. U.S. Fish. Com. for 1891, x1, pp. 409, 410; 7b., Braun, 1894, Centralbl. f. Bakt. u. Parasitenkde, xv, p. 86. Definition (provisional as regards negative characters).—Glugeide destitute of a myxosporidium and in which the pansporoblast produces an inconstant but large number (always more than 8) of spores; panspo- roblast membrane subpersistent as a polysporophorous vesicle; type, P. typicalis. 29. Pleistophora typicalis Gurley, 1893. (Corpuscles of Cottus scorpio Thélohan, 1890, Annal. de Microgr., 11, pp. 203, 212; ib. Thélohan, 1891, Journ. de Microgr., Xv, pp. 145, 146; ib. Thélohan, 1891, Compt. Rend. hebdom. Soe. Biol. Paris, 111, pp. 27,28; ib. of Collus (error) Thélohan, 1891, Compt. Rend. Acad. Sci. Paris, cxul, p.170; ib. Pfeiffer, Die Protozoen als Krankheitserreger, 2 ed., pp. 113-115; ib. Thélohan, 1892, Compt. Rend. hebdom.Soc. Biol. Paris, lv, pp. 82, 83; ib. Thélohan & Henne- guy, 1892, ibid., p. 586; ib. Thélohan, 1892, Bull. Soc. philomat. Paris, rv, pp. 165,174; ib. Henneguy & Thélohan, 1892, Annal. de Microgr,, Iv, pp. 618, 619, 622, 631, 636.) Pleisiophora typicalis, Bull. U.S. Fish Com. for 1891, x1, p. 410; 1b. Braun, 1894, Centralbl. f. Bakt. u. Parasitenkde, xv, p. 86. Cyst.—None. Spore formation.—Thélohan observed between the fibrillz small sepa- rate masses of protoplasm, each with a distinct membrane and nuclei. These masses were 4,11 long by 2°5 to 3u broad. Thélohan believed them to represent the first stages of development, but emitted this opinion with reserve, not having seen a sufficient series of stages. Some pro- toplasmic masses inclosing several nuclei exhibit, however, intermediate stages between the masses already described and the pansporoblasts. 14 Cent.” in Journ. de Microgr., xv, p. 146, 7. THE MYXOSPORIDIA, OR PSOROSPERMS OF FISHES. 195 Pansporoblast spherical, average diameter 15 to 18 4; membrane thin, transparent, containing, besides fully developed spores, sporo- blasts in different stages of development, some of them measuring 2°5 to 3 4, and containing one or several colored granules representing nuelei. Spore.—Ovoid, resembling that of Glugea anomala; length, 3 y; breadth, 1:5 to 2; a single capsule with a filament is present; large extremity showing a mass refractory to staining fluids, the remainder of the spore cavity containing sporoplasm, and a body apparently repre- senting the nuclear element of the spore, staining strongly with reagents, and in certain cases decomposable into separate granules whose num- ber never exceeds 4. Habitat.—Muscles of Cottus scorpio (sculpin); position interfibrillar. Effects —Diseased mass forming small white streaks of an averaye size of 5 to6 mm. by 3 mm., consisting of spores. The fibers affected increase in bulk; they are filled with the pansporoblasts disposed without regular order between the fibrille, which latter become sepa- rated and distorted, without, however, presenting any alteration of structure or diminution in the clearness of their tranverse striation. Ill, THELOHANIA Henneguy, 1892. Etymology: Thélohan. In Thélohan, Bull. Soc. philomat. Paris, 1v, p. 174, footnote; ib. Henneguy, in Henneguy and Thélohan, Annal. de Microgr., Paris, 1892, tv, p. 639; ib. Gurley, 1893, Bull. U. 8. Fish Com. for 1891, x1, pp. 409-410; ib. Braun, 1893, Centralbl. f. Bakt. u. Parasitenkde, xiv, pp. 739-740; ib. Braun, 1894, Centralbl. f. Bakt. u. Parasitenkde, xv, p. 86. Dejinition' (provisional as regards negative characters).—Gilugeide destitute of a myxosporidium and in which the pansporoblast pro- duces constantly 8 spores; pansporoblast membrane subpersistent as an octosporophorous vesicle; type 7. giardi.’ Henneguy and Thélohan remark that in this genus the spores unques- tionably approximate those of Glugea anomala and those of Pleistophora. The number of spores formed in the pansporoblast and the absence of a myxosporidium differentiate Thelohania from Glugea. On the con- trary, the last character and the subpersistence of the pansporoblast membrane as a sporophorous vesicle, approximate it to Pleistophora. 1 Henneguy’s definition is: ‘Spores pyriform, with one polar capsule at the small extremity and, at the opposite extremity, a clear vacuole with contents not colorable by iodine. Sporoblasty pro- ducing only 8 spores surrounded by an envelope persisting after theformation of these last; no plasmic mass, properly speaking.” As constituted by Henneguy the genus included only 3 species, T. octospora, T. giardi and T. contejeani. Type proposed by the author in Bull. U.S. Fish Com. for 1891 (1893), x1, p. 410. 196 REPORT OF THE COMMISSIONER OF FISH AND FISHERIES. 30. Thelohania contejeani Henneguy, 1892. Pl. 10, figs. 4, 5. ‘Parasite of crayfish, Henneguy and Thélohan, 1892, Compt. Rend. hebdom. Soc. Biol. Paris, Iv, p. 749.) Thelohania contejeani, in Thélohan, Bull. Soc. philomat. Paris, rv, p. 174, foot- note; ib., Henneguy and Thélohan, 1892, Annal. de Microgr., Iv,-pp. 637-9, pl. 4, figs. 26-7; ib., Braun, 1893, Centralbl. f. Bakt. u. Parasitenkde, XIV, pp. 739-740; ib., Dubois! (Raphzl) 1893, Recherches de pathologie comparée sur la peste des écrevisses, Compt. Rend. hebdom. Soc. Biol. Paris, V, pp. 158-9, figs. A,B; ib., Gurley, 1893, Bull. U. S. Fish Com. for 1891, x1, p. 410; ib., Braun, 1894, Centralbl. f. Bakt. u. Parasitenkde, Xv, p. 86; cf. La Maladie des Kerevisses en Allemagne; Bull. Mensuel Soe. Nat. @Acclimat. France, February, 1884, p. 200 (transl., Bull. U.S. Fish Com. for 1884, Iv, pp. 299-302). Cyst—None. Parasitic mass producing an opacity of the affected muscles, as in Palemon and Orangon. Opacity more difficult of obser- vation than in the last, on account of the greater thickness of the test; easily detected, however, on the inferior surface of the abdomen. Adult.—In some places only spores are seen; in others small plasma- spheres, containing a variable number of nuclei, occur. These are evidently developmental stages, but a full series could not be found. 1This observer noted 2 (entirely distinct) parasites, viz: one which Henneguy and Thélohan pronounced a fungus, and one which he determined to be Thelohania contejeani. 1. The former he describes as follows: Spore.—Cellules elongate, ovoid, cylindrical, or strangulated toward the middle, according to the degree of development. Shell double-contoured; protoplasm vacuolate, escaping amceboidly through a small lateral orifice. Spores apparently not capable of growth in nutritive fluids. Habitat.—Confined to the intestinal canal of the diseased crayfishes. The observa- tions were made in June and July (1892), the months of maximum severity of the epidemic. Crayfish epidemic.—Causes: Alterations of streams by industrial or agricultural products can have only a subordinate and local influence. Areainvaded divisible into 3 zones: (1) Lake Mantua (and its outlet to the sea, — the river Ain); formerly renowned for its crayfishes, which constituted an important revenue; now destitute of crayfishes. (2) The Merloz rivulet, an affluent of the lake, containing sound and diseased crayfishes, the latter showing the symptoms of the pest. (38) The sources or Doye des Neyrolles feeding the lake and the Merloz rivulet, from which latter it is separated by a dam, above which all the crayfishes are healthy. A The stoppage of its advance by the dam and its inability to growin nutritive fluids caused Dubois to suspect it to be an animal (possibly a sporozoan) which ascended the watercourse from the sea, perhaps brought bya fish. Thélohan and Henneguy, however, from an examination of his material, believed the form to be a fungus. The Distome described by Baer in 1827 (when no epidemic existed), to which Harz attributes the crayfish epidemic, was sought for in vain. : 2. Thelohania contejeani.—Feeding experiment: Sound crayfishes were isolated in reservoirs and fed, some with butcher’s meat, and others with the flesh of trout, carp, pike, and roach. After three months those fed on roach showed parasites in the abdominal muscles. This parasite was identical with Thelohania contejeani. Dubois asks: Do relations exist between the parasite found in the muscles and the intestines in October, and that found in July in the abdomen? THE MYXOSPORIDIA, OR PSOROSPERMS OF FISHES. 197 Spore formation.—Number of spores found in each sporigenous area variable, always, however, more than 8, in which respect the present species differs from the spores of Palemon and Crangon.! Spores some- times free, sometimes 8 together ina common envelope, as in Palemon.? Spore.—Size approaching and appearance the same as that of 7. octo- spora; ovoid, length 2 to 3 yu, with a clear vacuole in the larger end. Habitat—Striated muscles of Astacus fluviatilis (crayfish) from the Department of Doubs, France; collected by M. Contejean in 1890, Pathological anatomy.—On section the muscles show nearly the same appearance asin Paliemon and Crangon ; the fibrille being separated by parasitic masses, which in transverse sections appear as numerous deeply stained punctules, and which in longitudinal sections assume the appearance of irregular chains separating the fibrille; the latter have preserved their normal appearance, the strie being perfectly distinct. Nature.—The material was available only in alcohol, to which it had been transferred from Fol’s liquid. Owing to this, Henneguy and Thé- lohan were unable to demonstrate the capsule with filament. The similarity to the other species leads them, however, to believe it a myxosporidian. Hffects.—A notable diminution of muscular vigor was clearly estab- lished with the myograph by M. Contejean. Epidemics.—In the Department of Doubs this disease has raged with intensity among the crayfishes during several years and has caused the death of a very great number of individuals. It seems now to have disappeared. Moreover, this parasite can hardly be special to the watercourses of Doubs, and, remembering the considerable mortality caused by it in that Department, it is to be presumed that this hitherto unknown organism has played a role in the genesis of the epidemic which raged for several years in the East, and which has almost com- pletely destroyed the craytishes of that region. 31. Thelohania octospora Henneguy, 1892. PI. 10, fig. 6; pl. 11, figs. 1-5. (Parasite of Palamon rectirostris and of P. serratus, Henneguy, 1888, Mém. publiées Soc. philomat. Paris ’Occas. Centen. Fondation, pp. 163-71; ib., Thélohan, 1891, Journ. de Microgr., xv, p. 146; ib. of P.. rectirostris, Thélohan, 1891, Compt. Rend. hebdom. Soe. Biol. Paris, m, p. 28, name only; ib., Thélohan, 1891, Journ. de. Microgr., xv, pp. 146-7; ib., Pfeiffer, 1891, Die Protozoen als Krankheitserreger, 2 ed., pp. 114-5; ib., Thélohan and Henneguy, 1892, Compt. Rend. hebdom. Soc. Biol. Paris, Iv, p. 586.) Thelohania octospora in Thélohan, Bull. Soc. philomat. Paris, 1v, pp. 165-6, 174, footnote; ib., Henneguy and Thélohan, 1892, Annal. de Microgr., Iv, pp. 621-27, 629-632, pl. 4, figs. 1-8; ib. Gurley, 1898, Bull. U. S. Fish Com. for 1891, x1, p. 410; ib., Braun, 1893, Centralbl. f. Bakt. u. Parasitenkde, XIv, pp. 739-40; ib., Braun, 1894, Centralbl. f. Bakt. u. Parasitenkde, XV, p. 86. 1Henneguy and Thélohan, Compt. Rend. hebdom. Soc. Biol. Paris, 1892, 1v, p. 749. ?Henneguy and Thélohan, 1892, Annal. de Microgr., 1, p. 638. 198 REPORT OF THE COMMISSIONER OF FISH AND FISHERIES. Life history.—All the individuals, whether wholly or only partly invaded, showed the same developmental stage. It seems fair to sup- pose the first stage to be a plasmodioid mass in which the spores form. The constant presence of 8 spores suggests their origin by successive bipartition, as occurs with the falciform corpuscles of Gregarines (Hen- neguy, 1888). The stage of development of the parasite of P. serratus, taken in connection with the date of capture, indicates that the course of development of the parasite is the same in this crustacean as in P, rectirostris (Henneguy and Thélohan, 1892). OCyst—Henneeguy vainly endeavored to detect, even under very high powers and with different reagents, in material, fresh or fixed, disso- ciated or sectioned, a cyst membrane, and believes the cyst to be absent. This view is, he thinks, confirmed by the irregularity of the distribution of the pansporoblasts between the fibrille. Pansporoblast (“ vesicles” of Henneguy, 1888).—Rounded, diameter, 10 «; membrane thin, transparent, resisting potassium hydrate solution, apparently not presenting local thickenings as in 7. giardi. Spore formation.—Each pansporoblast produces 8 spores, which fill only a portion of its cavity and are disposed without order. Spore.—Length, 3 to 4 4; pyriform, very refringent; capsule present; length of filament 40 to 50 4; exit, produced, after failure of all other reagents, by ether, whose action is rapid and perfectly definite, and affects a large number of spores; usually extruded completely, some- times, however, only partially uncoiled ; capable of staining with anilin stains, among others violet 5B, The electivity of the filament for ether is a striking peculiarity. Habitat.—Interior of muscular fibers (between the ultimate fibrillz) of Palemon rectirostris Zadd (prawn), from the sait marshes at Le Croi- sic; the same seat in P. serratus from Conearneau and from Roscoff. In P. serratus less common than in P. rectirostris, in which latter it is (at least at Le Croisic) extremely frequent. It is never found in the diges- tive tract, nervous system, glands, sexual organs, or anywhere but in the muscles. Affinities.—By its exclusive seat in the muscles, and by the form and grouping of the spores, the parasite appears to be incontestably a sar- eosporidian, differing from those of the Mammalia in the absence of a surrounding membrane... The spores, also, are a little different from those of the other Sarcosporidia. They recall certain myxosporidian spores. This form also presents much affinity with the Microsporidia of the Arthropoda, the latter having the same refringent aspect and more or less oval shape of the present species, and being, like it, inclosed in “vesicles.” One finds them in all tissues, but not in the interior of the muscle fiber. There, then, probably exists a rather close relation between the Micro-, Myxo-, and Sarcosporidia, and the parasite of Palemon appears to represent a transition form between the 3 groups (Henneguy, 1888). THE MYXOSPORIDIA, OR PSOROSPERMS OF FISHES. 99 The discovery of the capsule settles the question in favor of its myxo- sporidian nature. It is thus neither a sarcosporidian nor a transitional form (Henneguy and Thélohan, 1892). Microscopic technique.—Henneguy fixed by alcohol, osmic acid solution, Flemming’s, Perenyi’s, or Kleinenberg’s liquids, dehydrated, paraffined, sectioned, affixed with Mayer’s albumen, and stained, preferably with gentian violet (Ehrlich’s) and eosin. Parasites (also nuclei of muscles, connective tissue, epithelia, nerves; which, however, can be washed out) violet; muscles rose-red. Picro-carmine; muscles red, spores yellow. Safranin; tissue nuclei red, spores same, but fainter. ; T. octospora differs from T. giardi in the smaller size of the panspor- oblast, and apparently also in the absence of thickening of its mem- brane. Pathological anatomy.—Macroscopic: Easily recognizable by the chalky or porcelaneous opacity’ which forms a constant and characteristic sign of the presence of these Myxosporidia. Opacity limited to the muscles invaded, consequently varying in extent with the degree of infection; in slight (and in the beginning of all) cases being limited to some white striz in one or several abdominal segments, or only one or two segments (most frequently then the first ones, the disease appearing to progress from before backwards) are opaque white. Ad maximum, the entire body becomes white except the region of the heart and stomach which always, and some parts of the claws, antennz, beak, and abdom- inal segments which usually, remain transparent. These exceptions constitute the only difference between this condition and the opacity produced by heat or alcohol. Microscopic.—Low powers: In examining a teased or slightly com- pressed muscle fragment, one immediately perceives, besides the normal primitive fiber bundles (easily recognizable by their transverse stria- tion), elongated spaces parallel to these bundles, contrasting strongly therewith, and apparently filled with a peculiar finely granular sub- stance. Dimensions of spaces approximating those of the normal fiber bundles; their transverse diameter, however, a little greater. Number of spaces varying pari passu, andthe intervening sound tissue varying inversely, with the intensity of the infection, the opaque spaces being in contact or more or less widely separated by sound fiber bun- dles. The proportion of the fibrille invaded is best appreciated in transverse sections of the muscles. In extreme cases nearly all the fibers may be affected. Longitudinal sections show the parasite in the form of violet chains between the rose-red normal fibrille (gentian violet; safranin). Higher powers: At first sight one would believe that each of these productions is entirely composed of a parasitic mass interposed between the primitive fibers, but a more thorough examination shows 'The same opacity is found in the muscles of Callionymus lyra, Cottus scorpio, and Barbus barbus, and outside the muscles the parasites exhibit the same color. 900 REPORT OF THE COMMISSIONER OF FISH AND FISHERIES. that each space corresponds to a primitive fiber bundle whose normal aspect is profoundly modified by the presence between its fibrille of elements of a parasitic nature, whence results a slight increase of width of the fiber bundle. Most often the fibrille do not present a sensible alteration. Sometimes (probably when a great quantity of the para- sitie element has led to a considerable separation) the elasticity of the fibrillxe is overcome, rupture resulting. Even under these conditions, however, the muscle strive remain exceedingly clear, no degeneration ever having been observed, as in Callionymus and the barbel. The nuclei of the muscle fiber are more numerous and smaller than normal; this feature is particularly well shown by safranin (Henneguy, 1888). Effects —The muscular vigor is considerably diminished. Thus, if a number of P. rectirostris living in the rivulets of the salt marshes be frightened out of their shelter among the vegetation, even although the new shelter sought by them be near at hand, the diseased white individuals (immediately recognizable against the strongly contrasted muddy rivulet bottom) lose grourd and remain considerably behind the sound ones. Further, one knows with what ease the prawns jump out of the vase in which they are held captive. If sound and opaque prawns be placed together in a basin, after some hours the sound ones have nearly all dispersed around the vessel, while the opaque are there still, or have only succeeded in sticking to the wall of the basin, how- ever small the bound required to overleap the barrier. Considering the intensity and universality of the muscle infection, the diminution of muscular vigor is quite natural; indeed, the surprising feature is the relatively great agility retained by muscles the bulk of whose con- tractile substance is much inferior to that of the parasite, and in some cases it is truly astonishing that muscular power is not completely destroyed. Among the diseased Palemons no egg-bearing females were seen. Perhaps this may be a case of “ parasitic castration.” The diseased individuals do not survive very long, all succumbing by the end of autumn, as during the winter not one can be found. Conditions and mode of infection The prawns affected are usually found in small shallow ditches containing a layer of water 0:10 m. to 0:20 m. deep, along the slope separating the compartments from the salt marshes. The water of these ditches is rarely renewed and acquires an elevated temperature. These are probably the conditions favorable to the development of the parasite. Itis difficult to decide whether the parasite finds an entrance by way of the alimentary canal. Hen- neguy seems to favor the contrary view, as the first lesions are found at places remote from the digestive tract. Artificial infection.—Captive Palemons fed for several months with diseased tissue showed no signs of infection. It was impossible to pro- long the experiment to see whether infection would ultimately ensue (Henneguy, 1888). P. rectirostris fed for months with diseased tissue ie all THE MYXOSPORIDIA, OR PSOROSPERMS OF FISHES. 201 never showed, under the most careful microscopic examination, the slightest trace of infection (Henneguy and Thélohan, 1892). Season.—Disease most frequent and at maximum of development from about July 15 to the end of August; number affected diminishing in September; diminution more pronounced in October; disappearing entirely after November 15; reappearing about March 15 or the first days of April. 32. Thelohania giardi Henneguy, 1892. PI. 12, figs. 1, 2. Crangon poe ate giardi. | Date. Authority; reference. etc., of. Se AR Seb Sepencsnas 1892 | Thélohan & Henneguy, Compt. Rend. hebdom. Soc. Biol. Paris, IV, pp. 586-7. Thelohania -| 1892 | Henneguy in Thélohan, Bull. Soc. philomat. Paris, IV, pp. 165, 174, footnote. Thelohania.| 1892 | Henneguy & Thélohan, Annal. de Microgr., IV, pp. 621, 624, 626-31, pl. 4, figs. 9-25. x 1893 | Ohlmacher, Journ. Amer. Med. Assoc., XX, p. 562. Thelohania .| 1893 | Gurley, Bull. U.S. Fish Com. for 1891, XI, p. 410. Thelohania .| 1893 | Braun. Centralbl. f. Bakt. u. Parasitenkde, XLV, pp. 739-740. Thelohania .| 1894 | Braun. Centralbl. f. Bakt. u. Parasitenkde, XV, p. 86. * Crangnon; error. Cyst unknown. Spore formation.—Pansporoblast spherical; diameter 14 jy (12 to 14 yw); in the young stages consisting of a very thin membrane resisting potassiuin hydrate, inclosing a very transparent, scarcely granular, slightly refringent protoplasin, having at its center a rather large nucleus (pl. 12, fig. 1a, b), often visible in the fresh state, becoming much clearer under the action of reagents. (1) Segmentation of the pansporoblast: The nucleus first presents the typical resting structure with a distinct membrane. The chromatin can take on different arrangements, sometimes formingone grain much larger than the others, sometimes a variable number of smaller sub- equal grains, or sometimes crowded back against the membrane, pre- senting here and there thicker portions (pl. 12, fig. 1). Subsequently a remarkable modification occurs: the chromatin has beconre arranged in filaments, the membrane has disappeared, and the nucleus assumes the arrangement known as the chromatic coil; very soon the chro- matic filaments orient themselves into a very distinct equatorial plate, which becomes double, the process resulting in the formation of 2 daughter-nuclei. We thus have atrue karyodieresis. The achromatic filaments were not seen, doubtless owing to their rather small size and partly, Henneguy and Thélohan believe. to the nature and optical proper- ties of the protoplasm. Protoplasmic segmentation soon follows nuclear division, and one sees, within the primitive pansporoblast membrane, 2 small distinct nucleated masses. In their turn these 2 masses divide and redivide, the process ending with the formation of 8 small plasmic bodies (sporoblasts) within the original pansporoblast membrane. The divisions do not take place very rapidly, and between successive ones 202 REPORT OF THE COMMISSIONER OF FISH AND FISHERIES. ) the nuclei have time to return to astate of rest, whence they again pass through the same stages preliminary to division. The sporoblasts have no regular arrangement within the pansporo- blast membrane; their shape is inconstant, varying with their arrange- ment; they generally approximate a truncate-pyramidal form. Each sporoblast develops into a spore. Spores thus contained 8 in each pansporoblast membrane, without regular arrangement, not nearly filling the cavity. Thisis the last stage of development reached in the muscles of the host. Pansporoblast membrane retaining its original dimensions, perfectly transparent, very thin, although the double contour is easily visible, showing in optical section marked thickenings, often 2 in number (pl. 12, fig. 1k). (2) Development of sporoblast into spore: Owing to the very minute size of these bodies, it is almost impossible to follow this development in detail or to confirm the facts discovered in the larger forms by Thélohan, viz, sporoblast segmentation, number of nuclei, ete. Development of capsule: A peculiar arrangement, believed to be connected with the development of the capsule, was noted, viz: often in the body of the sporoblast, near the nucleus, a clear rounded space, into which a small protoplasmic button projects. This observation is, how- ever, a very delicate one, and the figures are slightly diagrammatic. Morphology of the sporophorous vesicles—The constitution and develop- ment of the spore-producing vesicles permit us to consider them only as the morphological equivalent of the pansporoblasts of the other A/yzo- sporidia. These octosporophorous pansporoblasts form a transition from the oligosporogenetic pansporoblasts of the larger species to the polysporogenetic pansporoblasts of Glugea, which latter produce a con- siderable and inconstant number of spores. Above all, one fact is here to be noted, viz, the entire absence of a myxosporidium. No structure whatever could be detected which could be regarded as its morpho- logical or physiological equivalent. But whence come these spore-producing vesicles? Evidently they do not represent the first stage of development. Now if, as is usual, they are formed in the interior of a protoplasmic mass, what has become of the latter? In all other known species a considerable protoplasmic residue remains, even of myxosporidia whose development is completed, and in which young pansporoblasts are no longer to be found, but only entirely mature spores. But here are young pansporoblasts at their simplest (uninucleate spherules) with not the slighest trace of a sur- rounding protoplasm. As long as we had only found these organisms in the mature state (as sporophorous vesicles) that absence might have been explained, in case of necessity, on the supposition of a complete previous transformation of the myxosporidium into pansporoblasts, the myxosporidium vanishing in the process or leaving only insignificant vestiges. But in the presence of the now known earlier phases of development this hypothesis seems hardly admissible. THE MYXOSPORIDIA, OR PSOROSPERMS OF FISHES. 203 Henneguy and Thélohan add: Is it necessary to admit the existence of a plasmic mass [myxosporidium] which is completely transformed into sporoblasts? This mode of view can evidently be defended ; no fact, however, comes toits support, and it has the grave fault of deviating widely from what one knows of the development of the other species. On the whole we must admit that there is here a point in the history of our parasite which our researches have not elucidated, and the state under which it is presented constitutes a curious peculiarity which, at least in appearance, establishes an important distinc- tion between it and the other Myxosporidia. Abnormalities of development.—One rather frequently encounters spores which are larger than the others and which exhibit a constriction (pl. 12, fig. 11). At first view one is tempted to question whether this is not a phase of division. Similar productions are rather frequent in Glugea and in the Microsporidia (whose spores offer much resemblance to those of Thelohania), where they lave been seen by Pasteur,! who considered them as corpuscles in process of division. On the contrary, Balbiani, who has studied them with care, regards them as the result of malformations, a view which Henneguy and Thélohan adopt in the pres- ent species. If fig. 12, pl. 10, be considered, it is quickly seen that this is the only interpretation admissible. One sees there 4 normal spores, and 2 larger structures constricted toward their middle and presenting attenuated extremities similar to the small ends of normal spores. The appearance of these elements and their dimensions cause one to think of 2 spores soldered by their large extremities. There can no longer remain any doubt in this respect if one considers that by supposing these spores separated the typical number of spores in the pansporo- blast is made up. In reality, then, the 2 spores in question have, in consequence of an accident which has occurred in the course of their development and by a process which we have not been able to follow, contracted an intimate adhesion at the level of their large extremity, the point where this soldering has taken place remaining marked by a constriction. The limited number of spores in each pansporoblast ren- ders the proof much more easy here than in Glugea and the Microsporidia, where the number of spores is much greater and not constant. [I can not see why these could not be more simply and better explained as malformations, the result of development from imperfectly segmented pansporoblasts, i. e., as developing from a quarter-segment of the pansporoblast which failed to divide completely. The partial fusion of 2 spores where no pressure-atrophy of the shell could be assumed, seems very improbable. (cf. p. 180). R. BR. G.] Finally, although not pertaining directly to the Myxosporidia, in this connection the following from Kunstler and Pitres”? may be quoted: The small forms often show themselves constituted in such a manner that they appear to be in way of division (figs. 8-12). The multiplicity, the variety, and the constancy which these appearances present seem to show well that this is really a 1¥tudes sur les maladies des vers A soie, Paris, 1870. 2 Journ. de Microgr., 1884, vu, p. 522. 204 REPORT OF THE COMMISSIONER OF FISH AND FISHERIES. process of division. Some divide into 2 equal parts (fig. 8); in others the parts are of unequal dimensions (figs. 9, 10), and often this division recalls strongly a phe- nomenon of terminal or lateral budding (fig. 11). Spore.—Very refringent, pyriform; anterior end much more acute; length 5to 6 4; shell with very fine longitudinal striz; could not deter- mine whether bivalve or not. Capsule: In fresh material the highest powers reveal nothing suggest- ive of a capsule, the anterior extremity appearing merely more shaded, seemingly occupied by ahomogeneous, refringent substance. Onesome- times sees, however, near the anterior end, a clear streak (pl. 12, fig.1o) believed to be due to thecapsule, but it istoo indefinite and exceptional to prove the existence of that structure. Stained sections afford no aid here. Filaments: Extrusion not produced by iodine, potassium or sodium hydrates, glycerin, heat, acetic or formic acids, or by ether. Hydro- chloric and nitric acids produced extrusion; thelatter difficultly obtain- able, observed only in a very small number of cases in spite of repeated efforts. Strangely enough, this method failed completely to produce extrusion in 7. octospora and, on the contrary, ether, the only agent which succeeded in that species, was without effect on the spores of 7. giardi. Filament 15 to 20 4 long; usually extruded completely, some- times, however, extruded only partially uncoiled; susceptible to anilin stains, among others violet 5B. Sporoplasm: Safranin or gentian violet (apparently the best stains for these organisms) yield 2 different appearances, according to the degree of decoloration. If slightly decolorized, the vacuole alone is visible, but when decolorized ad maximum only some colored grains remain in front of the vacuole. Sometimes two or three are distin- guishable; most frequently, however, only a small colored band (appa- rently formed of fused granules of indeterminate number) is seen. Vacuole aniodinophile. Habitat—Seen only once in Crangon vulgaris Fabr. (shrimp), from Boulogne. Probably the course of development is the same as in Palemon, asin the single specimen taken the state of development of the parasite corresponded to the state of development in Palemon at the same date. Pathology.—Everything under YT. octospora relative to the opacity produced in the host applies equally to 7. giardi, except that, by reason of the less perfect normal transparency in, and the pronounced tegu- mentary pigmentation ‘of, Crangon vulgaris, the modification is less striking, though it is always sufficiently sharp to permit the recogni- tion of the infected individuals without any difficulty. EH ffects—Ehrenbaum!' noted abnormal individuals of a paler, more opaque color, destitute of the normal greenish tone, apparently con- siderably enfeebled, dying more rapidly than the normal ones when 1Zur Nalurgeschichte von Crangon vulgaris, Berlin, 1890, pp. 11, 12. oe ee THE MYXOSPORIDIA, OR PSOROSPERMS OF FISHES. 205 thrown out of the water.” The abnormal individuals never included egg-bearing females. This, Henneguy and Thélohan think, recalls the aspect of Crustacea infected by Myxosporidia. They have also never seen egg-bearing females among the infected Palemons. Perhaps we have. here, they think, another case of ‘“ parasitic castration.” Infection experiments.—A Caradina desmuresti fed for 71 days with the muscles of an infected Crangon, showed, on the most careful exami- nation, no sign whatever of infection. 33. Thelohania macrocystis Gurley, 1893. Pl. 12, fig. 3. (Sarcosporidian of Palemonetes varians Garbini,' 1891, Rend. Real. Accad. Lin- cei Roma, vil, Sem. 1, pp.. 151, 152 with fig.; myxosporidian of ibid., Thélo- han and Henneguy, 1892, Compt. Rend. hebdom. Soc. Biol. Paris, rv, p. 586.) Thelohania macrocystis, Bull. U. S. Fish Com. for 1891, x1, p. 410; ib., Braun, 1894, Centralbl. f. Bakt. u. Parasitenkde, xv, p. 86. Sporophorous vesicle.—Hlongate fusiform. ‘This is the principal char- acter distinguishing this species from T. octospora, which has perfectly rounded vesicles. Spores.—Hight in number, pyriform, shell difficultly stainable, col- oring only in a 0-5 per cent boiling solution of eosin; spores easily Stainable by Gram’s method; in the larger posterior end a distinet round “nucleus” more clear and transparent than the surrounding sporoplasm. ‘Together with these forms are others with a thicker and more difficultly stainable shell, within which 8 corpuscles are with diffi- culty discernible; probably these represent more advanced stages of the same parasite. Garbini failed to find other developmental stages corresponding to those found by Henneguy in T. octospora. Inocula- tion of healthy animals proved a failure. Habitat.—Occurring in great numbers in the muscles of Palemonetes varians (prawn) from the Mincio in the neighborhood of Verona. Nature——This species has much analogy with Thelohania octospora, but presents some noteworthy differences that warrant its specific sep- aration. Ordo II. Phenocystes Gurley, 1893. Etymology: gaivw, Lappear; xvoric, capsule. Bull. U.S. Fish Com. for 1891, x1, pp. 409, 410; ib., Braun, 1894, Centralbl. f. Bakt. u. Parasitenkde, xv, p. 86. Definition.— Myxosporidia, in which the pansporoblast produces few (1 or 2) spores; the latter relatively large, with distinct symmetry and 2 or more capsules;? type family, Myxobclida. 1 First described in Garbini’s “Intorno ad un nuovo microorganismo parassita del Palemonetes varians (title only); Atti Real. Accad. Lincei Roma, 1890, v1, p. 526; unpublished. 2Except Myxobolus unicapsulatus and M. piriformis. This qualification is omitted by Braun. : 206 REPORT OF THE COMMISSIONER OF FISH AND FISHERIES. Fam. MYXOBOLID Gurley, 1893. (Myxosporidiee! Perugia, 1891, Boll. Scientif., Pavia, x11, p. 28; Myxobo- lées Thélohan, 1892, Bull. Soc. philomat. Paris, Iv, pp. 178, 176.) Myxobolida, Bull. U. S. Fish Com. for 1891, x1, p. 413; Myobolea [Thél.] Braun, 1893, Centralbl. f. Bakt. u. Parasitenkde, XIv, p. 739; ib., Braun, 1894, Centralbl. f. Bakt. u. Parasitenkde, xv, p. 86. Definition.—Phenocystes, whose spores are destitute of antero-pos- terior, but possess bilateral, symmetry;”? capsules 2, in 1 group at the anterior end; a bivalve shell, the plane of junetion of whose valves is parallel to the longitudinal plane; an iodinophile vacuole; type (and only) genus Myxobolus. IV. MYXOBOLUS Biitschli, 1882. Etymology not given. Bronn’s Thier-Reich, 1, pl. 38, figs. 6-10, and of subsequent authors; ib., Lank- ester, 1885, Encycl. Britan., 9 ed., xrx, p. 855; i0., Thélohan, 1890, Annal. de Microgr., 11, p. 213; Myxosporidium® Perugia, 1891, Boll. Scientif., Pavia, XII, p. 23; ib., Weltner, 1892, Sitzgsber. Gesellsch. Naturf. Freunde Berlin, p. 34; Myxosporidium, ibid., p. 35; Myxobolus et Henneguya*t Thélo- han, 1892, Bull. Soc. philomat. Paris, Iv, pp. 176, 177; Myxobolus, Perrier, 1893, Traité de Zool., p. 460; ib., Gurley, 1893, Bull. U. 8S. Fish Com. for 1891, x1, pp. 411-13; ib. peas 1894, Centralbl. f. Bakt. u. Parasitenkde, XV, p. 86. Definition.—Characters, those of the aril. Henneguyais separated from Myxobolus by only 2 characters, viz, (1st) capsules constantly 2, and (2d) the presence of atail. Inasmuch, how- ever, as all the numerous typical Myxobolus species have 2 capsules, and only 2 species are known to deviate in this respect in the direction of capsule-reduction, the typical number of capsules in Myxobolus is 2; so that the 2 differential characters in reality reduce to the single one of the presence of a tail. This in itself is not sufficient to warrant a generic separation, especially in view of the entire accord between the tailed and uti tiled forms in regard to symmetry, similar position of the valves, exactly similar vacuole, nuclei, etc. Besides, it may be noted that it has been several times asserted that tailed and untailed forms occur in the same cyst. Thus Miiller,’ Lieberkiihn,® and Biitschli’ 1 Myxosporidium Perugia (synonym for Myzxobolus Biitschli?) proposed as type of Fam. Myxosporidiew Perugia, by the author in Bull. U. 8. Fish Com. for 1891, X1, p. 418. 2Except species which have suffered reduction of characters (Myxobolus unicapsu- latus, M. piviformis, M. inequalis). Perhaps M. strongylurus should be added. 3 Myxosporidium merlucit proposed by the author (Bull. U. S. Fish Cem. for 1891 (1893), x1, p. 413) as the type species. The name Myxosporidium, having been pro- posed as a new name for a genus formed by the fusion of several good genera each of which already possessed a name in good standing, must be suppressed. 4 Henneguya psorospermica proposed as the generic type by the author (Bull. U. 8. Fish Com. for 1891 (1893), x1, p. 413). 5 See Myxobolus sp. 61, p. 240. 6 Miiller’s Archiy.,1854, p. 6; Mém. Cour. et Mém. Sav. Etrang. Acad. Roy. Belg., 1855, XX vg, p. 37. 7Bronn’s Thier-Reich, 1882, 1, p. 597. This is probably only an opinion as to the consensus, and not an independent one. =) a? THE MYXOSPORIDIA, OR PSOROSPERMS OF FISHES. 207 have all asserted this condition. It is, however, almost impossible for me to believe that a tailed species is ever (except of course from break- age, and I have seen many spores deceptively broken) untailed or that an untailed species is ever tailed. I do not recognize as true tails those processes evidently monstrous (as shown by their aspect, their great rarity, their wide divergence from the typical forms, and the lack of transitions thereto) which are very rarely observed in untailed species. Thus I have seen among hundreds of spores of Myzxobolus oblongus such aform. But that (and also those reported by others belong, I suspect, to the same category) should not be confounded with a true tail. In other words, I believe the presence or the absence of a tail to be a good specific character, but not a generic one. Finally, even if the above observations should be admitted to be accurate, might not the conjunction be better explained on the supposition that the 2 forms were in the same tumor, but not necessarily (at least until proven) in the same cyst, i. e., produced by the same myxosporidium. Although such a close approximation of 2 different species in the same tumor has not been seen, Thélohan is authority for an equally close approxima- tion of 2 different genera in the renal tubules of Gasterosteus aculeatus and those of Pygostcus pungitius. Finally, in this connection pp. 245, 246 should be consulted. I saw Weltner’s results long after writing the above, and perhaps they may demand some modification of it. Shell.—This structure is bivalve throughout the whole of the genus, the valves being superior and inferior. Ribbons (‘elastic ribbons” of Balbiani).—These curious and prob- ably abnormal modifications of the ridge are found only in, and are described under, Myxobolus ellipsoides (p. 223). Tail (see also pp. 245, 250, 254).—This structure is found only in some species of Myxobolus. It was first noted by Miiller, who says! that it is merely asolid prolongation of the shell substance not containing any extension of the body cavity. This is also, I believe, the view of its structure entertained by all subsequent observers. Balbiani regards the tail as formed by the coaptation along the median line of his “elastic ribbons” (p. 223). The tail would thus consist of 2 lateral halves. This view may be safely rejected, as, if the tail is really composed of two halves,-the latter must be superior and inferior, and not right and left. The latter view of its structure (2 halves, superior and inferior) is taken by Thélohan,? who says that the tail is composed of 2 halves (the respective superior and inferior positions of which are necessarily implied, since he says the bifurcation always takes place in the longitudinal plane), whose occasional imper- fect coaptation results in the bifurcate condition frequently observed. Finally, since writing the above, f have been enabled, by the kind- ness of Prof. Seth H. Meck, to examine Myzobolus ef. linearis (p. 253), in 1 Miiller’s Archiv., 1841, p. 479. * Annal. de Microgr., 1890, 11, p. 206, 208 REPORT OF THE COMMISSIONER OF FISH AND FISHERIES. which the composition of the tail by the coaptation of a superior and an inferior half is easily demonstrable. In at least one species, however, this structure of the tail appears not to obtain. In Myxobolus macrurus the structure in question seems not to be a shell process at all, but an independent structure with dif- ferent optical and chemical properties. Although at first inclined to suspect the existence of the two lateral pieces (without the median piece; see p. 250) in the untailed forms, I was unable to detect any trace of them, as iodine failed to separate such a structure. Further, I was unable to prove the constancy of the initial posterior divergence of the valves which in M. macrurus I suspected to be correlated with the described structure of the tail. Sporoplasm.—Correlated with the typical number and position of the capsules is the characteristic peltate shape assumed by the sporoplasm. The shape and the topographic features of this structure are described in detail under Myxobolus macrurus (p. 251). The sporoplasm contains nuclei, an iodinophile vacuole, and “ granules.” Nuclei (see also “ granules” below).—These were first observed by Thélohan. He describes! the condition as follows: A series of spores properly stained shows some with 1 nucleus (frequently situated at or near the median cornua) and others with 2, 3, or 4 nuclei, everything pointing to their origin by division from the single one. The subse- quent ones appear to migrate at first outward and then backward. Vacuole (iodinophile)—Although visible on some of Miiller’s figures, Biitschli? was the first to direct attention to this structure. He described it as a nucleus, remarking that, though sometimes visible in the fresh state, it became more distinct upon the addition of acetic acid or iodine solution. He failed in his efforts to stain it, a result that he attributed to failure of penetration through the shell of the staining fluid. ® In 1889 Thélohan? corrected this erroneous interpretation, showing that the structure in question is a vacuole. Little differentiated in the fresh state (on account of similar refrangibility) from the sporoplasm, it becomes evident when the latter is coagulated by alcohol, acetic, nitric, or osmic acids, or by silver nitrate solution (2 per cent). Its chief micro-chemical characteristic is its extreme resistance to nuclear stains, which affect all the surrounding parts.’ Iodine alone stains it a brownish red, the remainder of the protoplasm taking a pale yellow hue. The iodine reaction exactly resembles that exhibited by glyco- 1 Annal. de Microgr., 1890, 11, p. 210. 2 Ztschr. f. wiss. Zool., 1881, xxxv, p. 636. 2Compt. Rend. Acad. Sci. Paris, c1x, pp. 919-920. For Perugia’s confirmation see M, merlucii, p. 248. 4Biitschli, indeed, states the contrary, but my own results are throughout in accord with those of Thélohan, as are also those of Perugia (Boll. Scientif., Pavia, 1891, x1, p. 24). — 0S ee ee THE MYXOSPORIDIA, OR PSOROSPERMS OF FISHES. 209 genic matter. The vacuolic contents further resemble the latter in being insoluble in alcohol. Spores kept in this liquid preserve their reaction towards iodine. The vacuolic matter shows a further resem- blance to glycogen in its solubility in alkalies. Acids modify it so that after their action it no longer exhibits the iodine reaction. Thélohan was never able to obtain the reduction of the cupro-potassium solution. Pfeiffer! regards it as a nucleus, as does also Weltner.? My own observations are in entire accord with those of M. Thélohan. The structure in question never colors with any staining reagents nuclear or plasmic. It stains (alcoholic specimens) with iodine, exactly as stated by Thélohan, and is, [ think, unquestionably a vacuole. The vacuole is single, subglobular, usually central or subcentral, differentiated negatively (unstained against a dark ground) by staining reagents, and positively (dark brown against a light ground) by iodine. Granules (‘ globules,” ete.)—As late as 1884, Balbiani® regarded these as latent capsular germs, destined to develop into accessory cap- sules at the period of reproduction. These granules appear to be of three kinds: 1. “Globules” present in fresh material. Those situated far forward (usually found at the side of, and apparently connected with, the capsule) were first observed by biitschlit in Myxobolus miilleri, and subsequently by Thélohan® in J. oviformis. I have also seen them in M.macrurus. According to Thélohan, these are fatty, as they blacken strongly with osmic acid and dissolve in alcohol. 2. “Granules ” distributed irregularly through the plasma are men- tioned by Biitschli (loc. cit.). 3. The pericornual nuclei. The “ gtanules” forming this series are 2 in number, minute, brilliant, subsymmetrically situated near both the lateral cornua and the posterior extremity of the capsule. These bodies were first noted by Miiller.© Subsequently (as above mentioned), Bal- biani regarded them as capsular germs. In 1881 Biitschli described at some length the different appearances presented by these bodies in Myvobolus miilleri (p. 220). 1Die Protozoen als Krankheitserreger, 1891, 2 ed., p. 17. 2 Sitzungs-Ber. Ges. Naturf. Freunde Berlin, 1892, p. 32. ’Compt. Rend. Acad. Sci. Paris, 1863, Lvu1, p. 160; ine sur les Sporozoaires, 1884, p.144. In the latter place he says: “One remarks in the cavity of the psorosperm other small corpuscles which appear as refringent globules to the number of 3 or 4, symmetrically disposed, often placed at the base of the twin vesicles. I have considered these small globules as vesicles with a filament in a rudimentary state, destined to be developed at the moment of reproduction, for at this moment the psorosperm contains 3 or 4 vesicles with fila- ments. Biitschli has attacked this manner of view, nevertheless I believe I should maintain it.” 4 Ztschr. f. wiss. Zool., 1881, xxxv, p. 637, pl. 31, fig. 2, 5 Annal. de Microgr., 1890, m1, p. 211, pl. 1, fig. 8. 6 See p. 240, pl. 28, fig. 6g. FC 14 210 REPORT OF THE COMMISSIONER OF FISH AND FISHERIES, Thélohan! was the first to recognize their nuclear nature. He first believed them to belong to the sporoplasm, supposing them to be situ- ated at its 2 antero-external angles (lateral cornua). Subsequently, from a study of capsule development, he’ regarded the bodies in ques- tion as persistent embryonal nuclei, the remnants of such development. He further expressed the belief that these nuclei could in some cases become detached from the capsules and engulfed in the sporoplasm. Pfeiffer? termsthem “safranophile corpuscles,” but does not comment upon their nature. In Myxobolus macrurus I have studied these bodies (which, from their position, may be termed pericornual nuclei) with great care, and with the following results, which apply especially to M. macrurus, but equally well to M. lintoni: 1. There can be no question whatever that they are nuclei, as they take nuclear stains and show nuclear structure. 2. Their presence or absence and their position (at least in the fully developed spore) appears constant for the same species. As regards constancy of position they contrast strongly with the third and fourth nuclei. 3. The only question is as to their seat. It will be seen above that they have been regarded as belonging to the capsule and also as belonging to the sporoplasm. Asis implied by this difference of opinion, their seat is by no means easy of determination, and, after much study, J am as yet uncertain whether they are capsular or sporoplasmie. Three appearances may sometimes be seen on the same specimen: (a) They appear in one focus-plane almost certainly connected with the infero-lateral cornu; or, (b) they appear almost as certainly attached tothe drawn-out posterior end of the capsule; or, (c) they appear discon- nected from both and appear to be borne on a broad triangular spur projecting inwards from the shell. An interpretation which seems possible is that each nucleus is imbedded in the sporoplasm near the tip of the supero-lateral cornu, whence it happens that optically its position almost exactly coincides with that of the posterior end of the capsule. In some species (Myxobolus cf. linearis, M. transovalis) I failed to find any bodies which on account of the constancy of their position, etc., I could regard as the pericornual nuclei, and this absence appears to be here as definite a specific character as does their presence in M, macrurus and M. lintont. 34. Myxobolus unicapsulatus Gurley, 1893. Pl. 13, fig. 1. (Psorosperm of Labeo niloticus Miiller, 1841, Miiller’s Archiv., p. 487, pl. 16, fig. 5 a-d; ib. Robin, 1853, Hist. Nat. d. Végét. Parasites, p. 299, pl. 14, fig’7.) Myxobolus unicapsulatus, Bull, U.S. Fish Com. for 1891, x1, p.414; ib. of Labro [error] niloticus Braun, 1894, Centralbl. f. Bakt. u. Parasitenkde, xv, p. 86. Cyst and myxosporidium unknown. 1 Compt. Rend. Acad. Sci. Paris, 1889, crx, pp. 920-1; ibid., 1892, cxv, p. 1097. 2 Die Protozoen als Krankheitserreger, 1891, 2 ed., p. 7. 7 — THE MYXOSPORIDIA, OR PSOROSPERMS OF FISHES. 211 Spore.—Ot the form and size of Chloromyxum dujardini. Capsule only 1, situated on one side of the anterior end, obliquely directed. Habitat.—On Labeo niloticus from the Nile. 35. Myxobolus piriformis Thélohan, 1892. Plate 13, fig. 3 (pars), 4 (pars); pl. 18. (Psorosperms of the tench (pars) Balbiani, 1883, Journ. de Microgr., VII, pp. 197-198, fig. 66 b,c, ? d—f; ib. (pars) Balbiani, 1884, Légons sur les Sporo- zoaires, pp. 125-6, fig. 47b, c, ? d-f; pl. 4, figs. 1, 2, 3A (pars)}, ? 3B,C; ? ib. (pars) Pfeiffer, 1890, Die Protozoen als Kranheitserreger, 1 ed., pp. * 48,55, fig. 16; ? ib. (pars) 1891, 2 ed., p. 132, fig. 56. Myxobolus piriformis, Bull. Soc. philomat. Paris, Iv, p. 177; ib., Gurley, 1893, Bull. U. S. Fish Com. for 1891, x1, p. 414; ib., Braun, 1893, Centralbl. f. Bakt. u. Parasitenkde, xiv, p. 739; ib., Braun, 1894, Centralbl. f. Bakt. u. Parasitenkde, xv, p. 86. Synonymy.—M. Thélohan informs me (letter, 1893) that : M. piriformis has very probably been seen by Remak, although his figures and his descriptions do not prove it absolutely (pl. 5, fig. 5). He does not figure the polar capsules, but his figures almost certainly belong to the species in question. Fig. 8 represents 2 spores from the kidney? of the tench, which I do not know to what species to approximate. The presence of 2 capsules separates them from MW. piriformis. The form of its spores and the small size of the capsules do not permit of its approximation to any of the forms that I have encountered. The typical spore of MW. piriformis contains but 7 polar capsule. As in all species, one can find monstrous spores which inclose 2 capsules, but they have seemed to me very rare. This species is often accompanied, above all in the spleen of the tench, by MW. ellipsoides. Almost all the spores with 2 capsules, represented by the authors, belong, I believe, to the spores, more or less monstrous, of this last species. Balbiani considered M. piriformis a degraded form of IM. ellipsoides. I have been able to convince myself that this mode of view is not correct. It is a species abso- lutely distinct and well characterized, as I have been able to determine by numerous observations. After reading the above, I restudied the synonymy as between this species and J. brachycystis, and can not but feel that all of Remak’s figures are referable to 1 species, which probably is, as Thélohan thinks and contrary to my former opinion,’ distinct from his M. piriformis. The following are the conclusions at which I have arrived: (a) Remak’s figures are referable to 1 species. His fig. 8 (referred to in the second paragraph of the above quotation) is not from the kidney but from the spleen. There appears to me to be, especially in view of Remak’s statements which tend to show that he considered the question carefully, no ground for a separation between these 2 developed spores 1 The figures in the rows on Balbiani’s plate Iv, fig.3, are numbered in order from left to right, in the reproduction of it on pl. 18, fig. 3. The proper specific refer- ences of some of the figures of groups 3 and 4, on that plate, are dubious. The fol- lowing is about all that can be safely said at present: Indeterminate: Figs. 3 B,C; 4d-f. (either MW. piriformis or M, ellipsoides). Myzxobolus piriformis: Figs.3 A, Nos. 1, 2,6; 40, c. Myzxobolus ellipsoides: Figs. 3 A, Nos. 3, 4,5, 7 (the last with some certainty, the rest probably, ‘“‘abnormal” spores); 4a. 2These spores (Remak’s fig..8) are from the spleen. 3 Bull. U. S. Fish Com. for 1891, x1, p. 409, second footnote, where it is stated that 1 Myxobolus species possesses, perhaps inconstantly, a single capsule. At that time I inclined to fuse M. brachycystis with M. piriformis. 912 REPORT OF THE COMMISSIONER OF FISH AND FISHERIES. of the spleen and the noncapsulate spores (developing spores; sporo- blasts), also from the spleen, shown in Remak’s fig. 5. And, finally, between the immature forms of fig. 5 from the spleen and the similarly immature forms from the kidney represented in Remak’s fig. 7, specific identity seems almost certain. Another argument which is especially worthy of note is the fact that the spores represented in all 3 figures are almost exactly the same size. Remak does not, it is true, state the dimensions in the text, but on the plate he gives the multiplication ratio for the figures, and calculations from careful neasurements of them show that all of them agree very closely. I therefore think, with Remak, that they are all one species. (>) That species is distinet from M. piriformis. Among the 3 criteria cited by Thélohan as distinguishing M. brachycystis from A. piriformis, viz, spore-form, presence of 2 capsules and their small size, especial emphasis should be laid upon the latter, that is upon the small capsular index. Cyst and myxosporidium unknown. Spore.—Pyriform; closely resembling a pumpkin seed; being flat- tened-ovoid with a very acutely prior aceee extremity. Length, 16 to 18 4; greatest breadth, 7 or 8 yu. Habitat.—Branchie and spleen of Tinea tinca L.; kidney of Misgur- nus fossilis. 36. Myxobolus inequalis Gurley, 1893. PI. 13, fig. 2. (Psorosperms of Pimelodus blochii Valenc., Miiller, 1841, Miiller’s Archiv., p 487, pl. 16, fig. 6a, b; ib. Mtiller, 1843, Rayer’s Archiv. de Méd. comp., pl. 9, fig.6; ib. Robin, 1853, Hist. Nat. des Végét. Parasites, p. 299, pl. 14, fig. 8.) Myzxobolus inequalis, Bull. U. 8S. Fish Com. for 1891, x1, p. 414; Myrobolus inequalis [error] of Pimelodes [error] blochii, Braun, 1894, Centralbl. f. Bakt. u. Parasitenkde, Xv, p. 87. Cyst and myxosporidium unknown. Spore.—Length, 11 yp (0:0052/’); breadth, 7p (0-0933'); capsules 2 of unequal size. Habitat—On Pimelodus clarias Bloch (= Stlurus clurias Valence.) from Guiana and Surinam. 37. Myxcbolus brachycystis sp. nov. Pl. 1, figs. 1-3. (Psorosperms of Tinca chrysitis, Remak, 1852, Miiller’s Archiv., pp. 144-146, pl. 5, figs. 5, 7, 8.) Compare carefully p. 211. Remak compares it (by reference to Miil- ler’s figures) to Chloromyxum dujardini. Spore formation.—Pansporoblast: Oval vesicles usually situated on the walls of the blood vessels of the kidney or spleen; either in connec- tion with, or separate from, the pigment follicles; pansporoblast always monosporogenetic. In the developing spores Remak not infrequently missed the capsules, but comparison with developed forms which occurred in other eases left no doubt as to their nature, Spore.—Pyriform, long drawn out. Habitat.—Remak gives this as the pigment follicles of the spleen and THE MYXOSPORIDIA, OR PSOROSPERMS OF FISHES. Zio of the kidney of Tinea tinea L. (tench). He further asserts that the same form is found on the branchize, but as he does not figure any spores from the last seat it may perhaps be a question whether the branchie yield the present species in addition to W. piriform?s. In the kidney a 3-chambered pigment cyst was seen 27 yw (4/’’) long, the end compartments of which were occupied by pigment and the central one by a pyriform spore.’ The pigment-follicles of the spleen almost always contain untailed psorosperms in considerable numbers, lying without order between the pigment-holding cells. The pigment follicles of the kidneys always contain the same species as that found in the spleen and upon the gills (Remak). 38. Myxobolus ? sp. incert. PI. 14, fig. 4. Psorosperms of Cyprinus tinca, Lieberkiihn, 1854, Miiller’s Archiy., pp. 6, 24, 359, pl. 2, figs. 21-27. » Lieberkiihn’s description is substantially as follows: Cyst imbedded in cornea immediately under the inner surface. Upon slight pres- sure very many spores, partly with and partly without tail-like appendages, and whose shell was no longer smooth but wrinkled, and whose capsules were no longer together but occupied unusual positions, were seen. Individual shells contained only 1, and others no capsule. A number of free “nuclei” which had preserved the elub-shape of those within the spore also were seen. Finally, very small diaphanous, nongranular, ameebiform corpuscles occurred, which plainly, though slowly, moved with blunt or sharp processes. Habitat.—Encysted in cornea of Tinea tinca L. (tench). Concerning these figures, Thélohan (letter to author, 1893) says that they are not to be approximated to M. piriformis. Lieberkiihn’s fig. 21 would, he says, rather suggest Chloromyxum dujardini. 39. Myxobolus ? mugilis Perugia, 1891. Pl. 14, figs. 5, 6. Myzxosporidium mugilis Perugia, Boll. Scientif., Pavia, x11, pp. 23-24, plate, figs. 7,8; ib., Weltner, 1852, Sitzungsber. Gesellsch. Naturf. Freunde Berlin, p.35. Myxobolus mugilis Thélohan, 1892, Bull. Soc. philomat. Paris, tv, p. 166; ib., Gurley, 1893, Bull. U. S. Fish Com. for 1891, x1, p. 414; ib. Braun, 1894, Centralbl. f. Bakt. u. Parasitenkde, xv, p. 87. Cyst membrane.—Having removed with care one of the cysts from the branchize of M. capito, Perugia observed it to consist of 3 (others contain 2) separated myxosporidia surrounded by a common investing membrane evidently derived from the branchial lamella, which latter at no point showed any solution of its continuity. From this he concluded that the cyst is a production of the host. Some eysts contain 2 or 3 myxosporidia filled with spores, and with a residue of a very few granu- lations of protoplasm. Myxosporidium not described. Spore.—Free; ‘without a proper membrane” ?; length, 7. Habitat.—Encysted in the branchial lamelle of Mugil auratus and of M. capito (gray mullets). Rare; found only twice in 300 Mugils. ' Remak here erroneously refers to his fig. 5a instead of fig. 7A. ?From other similar expressions by the same author I interpret this to mean: ‘No pansporoblast membrane,” 914 REPORT OF THE COMMISSIONER OF FISH AND FISHERIES. Relative to its generic relations Perugia says: This form might be referred to the genus Myxobolus, from which it seems to me to dilfer only by alittle. The different hosts and the form of the spores only might cause it to be regarded as a distinct species. 40 Myxobolus sp.incert. Pl. 14, fig. 7. (Psotvsperm of Nais proboscidea, Lieberkiihn in Biitschli, 1882, Bronn’s Thier- Reich, 1, p. 590, pl. 38, fig. 23; ib., Thélohan, 1890, Annal. de Microgr., II, p. 193; ib. Pfeiffer, 1890, Virchow’s Archiv. f. pathol. Anat. u. Physiol., CXXII, p. 557; ib. Braun, 1893, Centralbl. f. Bakt. u. Parasitenkde, x1v, p. 739.) No description. Its symmetry shows it to be a Myxobolus. Observed by Lieberkiihn, and communicated by him to Biitschli; published only by the latter.! Habitat.—Nais proboscidea (a worm). 41 Myxobolus sp. incert. Pl. 15, figs. 1-6. Psorosperms of Esox lucius, Lieberkiihn, 1855, Mém. Cour. et Mém. Say. Etrang. Acad. Roy. Belg., XXvVI, p. 37, pl. 10, figs. 10-12, pl. 11, figs. 1-4; ? ib. Biitschli 1882, Bronn’s Thier-Reich, 1, pl. 38, fig. 11. Cyst.—Size 8 mm. (0°31 inch) by 4:25 mm. (0°17 inch); contents “ granu- lar matter” alone, spores alone, or both “ granular matter” and spores, in variable proportion. Myxosporidium unknown. Spore.—Oval or circular, tailed or untailed; the 2 kinds often mixed without order in the same cyst. Habitat.—Cysts of branchiz of Lucius lucius L. (pike). It is hard to know what to do with this form. In spite of his asser- tion that tailed and untailed forms occur in the same cyst, Lieberkiihn appears to figure only untailed forms. In view of this, and provision- ally until some other observer shall confirm this observation, I prefer to recognize this as a “form” distinct from the tailed one having approximately the same habitat. (See also p. 256.) 42 Myzxobolus oviformis Thélohan, 1892. Pl. 14, fig. 8. (‘‘Myxosporidian spore (MM. miilleri Biitschli?)” of Cyprinus carpio and of Gobio fluviatilis,? Thélohan, 1890, Annal. de Microgr., 11, pp. 200, 204, 209, 210, 211, 213, pl. 1, figs.8-11; spore of C. carpio, Thélohan, 1890, Compt. Rend. Acad. Sci. Paris, Crx, p. 921). Myzxobolus oviformis Thélohan, Bull. Soc. philomat. Paris, tv, p. 177; ib., Gurley, 1893, Bull. U.S. Fish Com. for 1891, x1, p. 414; ib., Braun, 1893, Centralbl. f. Bakt. u. Parasitenkde, xiv, p. 739; ib., Braun, 1894, Centralbl. f. Bakt. u. Parasitenkde, Xv, p. 87. Cyst and myxosporidium not mentioned. Spore.—Flattened-ovoid, with notably attenuate anterior extremity; length, 10 to 12 4; breadth, 84; capsules relatively large (6); nuclei ad plur., 3; vacuole, present. 1 Braun’s language is slightly ambiguous: ‘Eine iiltere Notiz, von Lieberkiihn, erwihnt” the occurrence of Myxosporidia in invertebrates. 2 An ambiguous expression of Lieberkiihn’s (Bull. Acad. Roy. Belg., 1854, XXxI, pt. 2, pp. 22-23) may refer to an observation of a species upon the branchiz of this fish. THE MYXOSPORIDIA, OR PSOROSPERMS OF FISHES. 215 Habitat—Common on fins (where the spores exist in great numbers in the subeutaneous tissue) of Gobio gobio L. (gudgeon); same fish, of Cyprinus carpio L. (carp), and of Alburnus alburnus L. 43. Myxobolus ? cf. oviformis. branchize of Psorosperms of Cyprinus carpio, Balbiani, 1883, Journ. de Microgr., vil, pp. 199- 201; ib., Balbiani, 1884, Légons sur les Sporozoaires, pp. 128, 130, 131. Cyst and myxosporidium not mentioned. oe Spore.—Length 18 nx; breadth 12 ju. Habitat.—On Cyprinus carpio L. (carp). The dimensions differ so markedly from those of M. oviformis that on the present evidence [ have not felt justified in fusing the 2 forms. It is, however, worthy of note that the ratio between the dimensions is the same as that in M. oviformis, and also that “18” may not impossibly be an error for 8. M.Thélohan writes that he has never found in the carp spores measuring 18 by 12 yw, and suggests that these dimensions may be an error. 44. Myxobolus sp. incert. Pl. 15, fig. 7. Authority; reference. Cyprinus | Gobio fluvia- brama, tilis [error] “* pnsoro- myxospo- | Date. sperms,”’ ridian spore etc., of— of— Chari weal a2 cet nace 1841 x sadAoch oueoes 1854 Ks WeeeeShe Sogeose 1879 x 1882 x 1882 BSP GShagerssbs - 3 | 1886 . Se) We8boseeeseaect 1887 Miiller, Miiller’s Archiv., pp. 491-2 Lieberkiihn, Miiller’s Archiv., Dp. 368, pl. 14, figs. 7, 8. Leuckart, Die Parasiten des Menschen, p. 248, fig. ‘990. Biitschli, Bronn’ s Thier- Reich, I, p.6 Lieberkiihn in Biitschli, Bronn’s iihiow-Reich, I, pl. 38, tig. 18a-c. Leuckart, The Havanites of Man, 2 ed., p. 197, fig. 99B. Koch, Ene Pee Sesamint. Thierheilkde u. Thier- zucht, IV, p. 94, fig. 668, 2,3 Biitschli’s reference to Gobio fluviatilis is certainly an error. figs. 18b and 18¢ (loaned him by Lieberkiihn) are respectively copies of Lieberkiihn’s figs. 7 and 8. That they are not merely independent figures of specifically identical material can be seen from the identity of the figure of the ever-varying ameeboid (fig. 8, Lieberkiihn; fig. The question is, moreover, additionally settled by Prof. Biitschli’s statement that— Concerning the subsequent fate of the spore, only two observers, Lieberkiihn and Biitschli; see pl. 15, fig. 7c). Balbiani, have so far expressed opinions. His 18e, They agree that the spore-shell finally separates, the protoplasmic contents emerging as a small active ameboid body (188, c). Thus the 2 figures in question were copied. Further, Lieberkiihn mentions a ‘“ psorosperm” from the body cavity of Gobio fluviatilis (see p. 243), and describes in detail his observations in that form upon the separation of the valves and the exit of the ameboid posterior mass. He makes no mention, however, of any forms upon the branchize of Gobio fluviatilis. The fact that Biitschli cites its habitat as the branchiz, with his statement that in this matter he is quoting, estab- 216 REPORT OF THE COMMISSIONER OF FISH AND FISHERIES. lishes the conclusion that his reference to Gobio fluviatilis was due to an erroneous correlation between Lieberktihn’s text and Lieber- kiihn’s figures. Finally, Biitschli’s fig. iSa appears to be the transverse view of 18d. Concerning the relation between this form and MV. sp. 45, M. Thélo- han (letter to author, 1893) says: It is impossible to say whether this figure should be approximated to my Myxobolus of the bream. No description. Habitat—Branchie of Abramis brama 1. (bream). 45. Myxobolus sp. incert. Myxobolus of bream, Thélohan, 1892, Bull. Soc. philomat. Paris, rv, p. 178. Cyst and myxosporidium not mentioned. Spore.—Length, 8 3 breadth, 6 to 7 py. Habitat.—Branchie of Abramis brama (bream). Remarks.—Differs from M. miillert only in the smaller size of the spores. See also remarks on the preceding species. 46. Myxobolus miilleri Biitschli, 1882. Pls. 16, 17. (Myxosporidian spores of Squalius cephalus, of Barbus fluviatilis, and of other fresh-water Cyprinoids, Biitschli, 1881, Ztschr. f. wiss. Zool., Xxxv, p. 630, footnote, pp. 630-8, 646-8, pl. 31, figs. 1-24.) Myxobolus miilleri, Bronn’s Thier-Reich, 1, pp. 595-7, pl. 38, figs. 6-10; ib. Lan- kester, 1885, Encycl. Britan., 9 ed., x1x, p. 855, fig. xv, 40, 415 1., Leunis, 1886, Synopsis d. Thierkde, 11, pp. 1157-8, figs. 1118-9; ib., Thélo- han, 1892, Bull. Soc. philomat. Paris, 1v, pp. 166, 167, 178; ib., Gurley, 1893, Bull. U. S. Fish. Com. for 1891, x1, p. 414; 1b., Braun, 1893, Centralbl. f. Bakt. u. Parasitenkde, xiv, p. 739; ib., Braun, 1894, Centralbl. f. Bakt. u. Parasitenkde, Xv, p. 87. Synonymy.—Biitschli (1881) says the Myxosporidia investigated by — him came principally from the Cyprinoids, but that he could not give the species of host exactly, as he investigated large numbers of excised branchize. In part, however, these latter were derived from Squalius cephalus and from Barbus fluviatilis. He further states that he was unable to recognize any specific distinctions between the spores of the series he examined. Biitschl’s type figures of 1882 are copies of his figures of 1881. Parenthetically, also Lankester’s and Leunis’s are copies of these. Of those who have studied the pathogenic muscle- form of Barbus barbus (=fluviatilis), all admit its close similarity to, and some assert its identity with, M/. miilleri (see p. 225). Further, Pfeiffer states that in the Rhine basin, in which the epidemic produced by the muscle-form is very extensive, the branchivw are free from Myrospori- dia, & nonassociation that would seem to favor the idea of specific dis- tinetness. So far, then, no direct comparison has been made between _ the spores inhabiting the branchi of B. barbus and those inhabiting the muscles of the same fish. In the meantime it is probable that Leuciscus (squalius) cephalus L. should be regarded as, so to speak, the type host of M. miilleri, \ Be i “Sle ore eee eae THE MYXOSPORIDIA, OR PSOROSPERMS OF FISHES. 217 Cyst.'.—Exelusively confined to the branchial lamelle, appearing by reflected light as white pustules, usually elongate-oval, 2 to 3mm. long; with greater development distending the flat branchial lamella. On closer examination of the freshest possible branchiz, the cysts are seen to be neither extra-, nor intra-, but sub-epithelial, the blood vessels of the mucosa running over their surfaces. Their seat is thus the submucous connective tissue layer which immediately surrounds the supporting central cartilaginous rod of the lamella, and which underlies each and separates both of the layers of inucous membrane, which latter form the opposite faces of the lamella and in which run, super- ficially, the afferent and efferent blood vessels and the capillaries of the mucosa. One can easily convince himself of this situation of the myxosporidium by external observation. One then remarks that the transverse-running capillaries superficially girdle the myxosporidium. A transverse section through the mass thus shows the supporting cen- tral cartilaginous rod girdled by the myxosporidium, and the latter in its turn surrounded by the vascular layer of the mucosa. If the myx- osporidium attain a greater growth, it naturally distends the lamellee — more and more, and, since the transverse capillaries girdle the myxo- sporidium ring-wise and oppose an obstacle to its expansion, the latter structure bulges out, sac-like, in the intervals between them, its whole outline being thus multilobate. From some further observations on very large myxosporidia, Biitschli believes that finally, through the continued growth of the myxosporidium, the restraining capillaries become ruptured, which explains the blood extravasations observed by him in the superficial portions of large myxosporidia, the girdling capillaries in these cases being absent. Membrane: By eareful manipulation the myxosporidium can some- times be removed intact from its seat in the branchiz. In both of the two successful instances, Biitschli observed a distinct membrane which possessed special interest in differing from the type usual among the unicellular organisms and particularly from that found in the Gregarines. Itis of a plasmatic nature, being composed of clear, very finely granular protoplasm, in which numerous small nuclei are imbedded. Neither acetic acid nor staining reactions show any evidence of cell outlines. The finely granular nuclei possess a distinct dark membrane, show a somewhat irregular outline, and stain intensely with alum carmine. It is difficult to determine with certainty whether this membrane is a production of the myxosporidium or of the tissues of the host. As opposing the former view (a view which, however, Biitschli considers as in no wise excluded) is the fact that the nuclei of the membrane are somewhat larger than those found in the endoplasm. 1The description is Biitschli’s. He calls it the myxosporidium, but it appears from his description to be the cyst (which, however, is probably only a later stage of growth of the imbedded myxosporidium). Pfeiffer erroneously states that these observations were madeupon Perca fluviatilis (Die Protozoen als Krankheitserreger, 2 ed., 1891, p. 130). 218 REPORT OF THE COMMISSIONER OF FISH AND FISHERIES. Myxosporidium.—Myxosporidium usually showing no clear difieren- tiation of ectoplasm and endoplasm except in thin sections, where certain portions exhibit very plainly a tolerably thick, granule-free exterior zone, possessing a great interest on account of its very distinct fine radiate striation. Endoplasm thickly studded with very small but distinct nuclei which in thin sections are, even in the fresh state, rather plainly visible as faint roundish corpuscles, in which dilute acetic acid differentiates a dark somewhat granulated membrane, a small dark nucleolus, and, sometimes quite clearly, fine nuclear threads radiating from the nucleolus to the membrane. This structure, together with their intense affinity for stains, permits no doubt as to their nuclear nature. Spore formation.i—This species never shows a paired spore-develop- ment, or a development within a pansporoblast (?; see below), the spores being directly imbedded in the endoplasm. ‘These spores, how- ever, Show indications of a similarity in their development to the other My«xosporidia in their origin from a trisegmented (‘ trinucleate”) plasma- globule, 2 of whose segments develop the capsules and the third the sporoplasm. Development of spore.2—In the myxosporidium, inclosed in a delicate membrane, a number of mature spores are seen, many things pointing to their origin from the protoplasm. They always contain 3 pale, almost spherical, but somewhat angular bodies. The membrane fre- quently shows an excavation and an opening at one end. At this end the 2 protocysts are situated, the protosporoplasm being remote there- from. Further observation shows the protosporoplasm to develop into the sporoplasm of the mature spore and the two protocysts to give origin to the capsules. The latter structures develop within the proto- cysts, the filament appearing first in the extruded condition, apparently forming a prolongation of the capsular wall. Subsequently, in the light of his observations on the development of Myxidium lieberkiihnii, Biitschli inclined to interpret thus: That the 3 spheres (viz, the 2 protocysts and the protosporoplasm) represent not plasma-spheres but nuclei, the latter being, on this supposition, imbedded in a plasma mass which he had failed to see, probably on account of strong swelling and great transparency. The observations of Balbiani and of Thélohan, however, render it almost certain that Biitschli’s observations were accurate and that his subsequent interpretation was erroneous (see also pp. 82, 223). Upon this view the present species would seem to develop pansporoblasts, each with a single spore. Spore.—Lenticular-oval, anterior end sharpened, showing quite plainly a shallow funnel-shaped depression; posterior end rounded off; dimen- sions 10 to12 u by 9 to il uw. On vertical view, contour rather variable, 1 Biitschli, 1882, Bronn’s Thier-Reich, 1, p. 597. 8The description is Biitschli’s (Ztschr. f. wiss. Zool., 1881, xxxv, pp. 646-8). ee THE MYXOSPORIDIA, OR PSOROSPERMS OF FISHES. 219 often almost circular, anterior end only slightly attenuated, border of suture exhibiting folds or crimpings varying in number from 7 to 9. Shell: Substance dark and somewhat glittering, possessing a marked resistance to chemical reagents; warmed with concentrated sulphurie acid the valves fall apart; stronger heating effects their complete destruction. Valves 2, superior and inferior, with a tclerably thick ridge or welt along the border (line of junction), visible very plainly as a ridge on transverse view. Capsule: Wall tolerably thick, glittering, inclosing a cavity occupied by the coiled filament which appears paler than the wall; showing, with the normal extrusion of the filaments, a very noticeable diminu- tion of volume, whence the conclusien that (as with the thread-cells proper) such extrusion is the result of the pressure of the stretched elastic capsular walls. The capsules are destroyed by gently warming with concentrated sulphuric acid. Filaments extruded under the influence of potassium hydrate solution, glycerin, and especially con- centrated sulphuric acid; also by mechanical pressure. The extrusion produced by the last means is frequently abnormal and very irregular, the filament being ejected ina more or less spiral form, or only incom- pletely, or sometimes through arupture in the capsular wall, either into the shell cavity, or through the shell, or, in the last case, more probably between the (by the pressure) partially loosened valves. Biitschliaddsa few interesting remarks to the effect that the capsules, so constant in the Myxosporidia, doubtless have some important and yet to be discov- ered function. Sporoplasm: Mostly very delicate, cloudy, granulated, nearly filling the posterior portion of the shell cavity, projecting forward im the median line and on the outer side of the capsules; this projection could not be traced all the way around the capsules. Containing a variable number of granules. Vacuole,! frequently quite plainly visible even in the fresh state as a circular or oval clear spot. It becomes more prominent, however, after the addition of dilute acetic acid or iodine solution and then shows @ dark, somewhat granulated membrane and a number of rather pale granules strewn through the contents, resisting all stains,” according to Biitschli sometimes invisible, a result that he attributes to great condensation of the protoplasm. Some spores appeared to possess 2 vacuoles, but upon this point Biitschli was not certain. 'This is Biitschli’s description of his ‘‘ nucleus.” 2A circumstance explained (but erroneously) by Biitschli as being due to a failure of the stain to permeate the shell. He says the nonstaining can not be taken as a contraindication of the nuclear nature of the structure in question, as the protoplasm also resists the stain. From my own experience I should say that would depend on the kind of stain used, plasmatic stains generally being, nuclear stains generally not being, retained. 2991) REPORT OF THE COMMISSIONER OF FISH AND FISHERIES. ‘“Granules.”—Biitschli summarizes his results thus: There are very constantly found in the protoplasm 2, or sometimes more, strongly refractile glittering granules of a roundish form, They are usually, though by no means always, situated tolerably symmetrically, just at the posterior ends of the polar capsules. No decided regularity obtains either as regards the number or position of the granules, as they are sometimes placed farther forward between the capsules, and sometimes are strewn entirely irregularly through the plasma. I have also observed, with longer preservation of the spore in water, an appearance which was not clearly intelligible, but which I will briefly describe. In spores so preserved one sees after some time nothing more of the 2 dark granules usually present, but on the other hand one sees on cach polar capsule posteriorly a dark punctule which occupies nearly the same position as the above-mentioned granule. It gives the impression as though the dark granule had fused with the capsular mem- brane and had developed into the punctule. I must, however, regard the interpreta- tion mentioned as a mere conjecture. Effects —Invades the connective tissue and ovules of Phoxinus phoxt- nus (Thélohan, 1892). Habitat—Branchize of various cyprinoids, particularly Leuciseus (Squalius) cephalus L.; Barbus barbus L. (barbel), both jfide Biitschli. Fins of L. cephalus; kidney and ovary of Phovinus phoxinus L., and on Crenilabrus melops at Roscotf (Thélohan). 47. Myxobolus? sp. incert. Psorosperm (second species) of Platystoma fasciatum Miiller, 1841, Miiller’s Archiy., p. 489. Cyst and myxosporidium unknown. Spore.—Oval, untailed; size equals that of M. sp. 61. Habitat.—On branchial arches (especially at their angles where the mucous membrane is soft) of Pseudoplatystoma fasciatum. 48. Myxobolus bicostatus Gurley, 1893. 1.19, fig. 1. (Myxosporidian spore of Tinca vulgaris, Lieberkiihn in Biitschli, 1882, Bronn’s Thier-Reich, 1, pl. 38, fig. 19.) Myxobolus bicostatus, Bull. U. S. Fish Com. for 1891, x1, p. 414; ib. Braun, 1894, Centralbl. f. Bakt. u. Parasitenkde, xv, p. 87. No description. Habitat.—Branchie of Tinea tinca L. (=vtlgaris), tench. This species is distinguished from M. ellipsoides by its larger capsular index (0-50 as against 0°33 in IM. ellipsoides) and by the 2 oblique ribs ov the shell. THE MYXOSPORIDIA, OR PSOROSPERMS OF FISHES. Dark 49. Myxobclius ellipsoides, Thélohan, 1892. Pl. i3, figs. 5, 4!; pls. 18, 20; pl. 19, figs. 2-8; pl. 21, figs. 1, 3d, 5, (2? 2, 3a-c,c; ??4; ? pl. 22, figs. 1-3). Tench Pike, “psoro- | [Error] sperms” | ‘‘psoro- | Bais Date. Authority; reference. of, spores) sperms” | 2 of, ete. of. | = | > lw Bacaeeeeee eeraneeccate | 1863 | Balbiani, Compt. Rend. Acad. Sci. Paris, LVIT, p.160. Se yay | CS eae a | ae ee 1864 | BYtibiani, Gaz. Méd., Paris, XIX, p. 146. ee lee Gy 1h eae ee ea 3 1874 | Moreau, Compt. Rend. Assoc. france. Avance. Sci., 2° | (Lyons) Sess., p. 814. Bg Seca ae Cee eee [evo eare ater 1883 | Balbiani, Journ. de Microgr., VII, pp. 199, 201-2, | | 272-4, 276-9, figs. 40, 61-3, 65a (see p. 211). x eves eisis am 2 eth ceo 1884 | Balbiani, Lécons sur les Sporozoaires, pp. 127-8, 130, | 137-40, 142-6, 148, figs. 36, 42-44, 46a; p).3, fig. 9; | | pl. 4, figs.1-8 (pars; see p. 211). x aac. Cees eee ess 1886 | Railliet, Elém. Zool. Méd. et Agric. Paris, pp. 167-8, | | fig. 72. eh eee oSCeteree 1887 | Pfeiffer, Ztschr. f. Hygiene, ITI, p. 475, fig. 2 e, f, g. x | x [eee Uae ot. z | 1888 | Pfeiffer, Ztschr.f. Hygiene, LV, pp. 409, 417-20, fig. | | 15 a-c. j < So SSSR SoEeene Se | 1889 | Henneguy, Dict. Encyclop. d. Sci. Méd., p. 775, figs. 2a-h. A wai eee. eects | 3889 | ‘Phélohan, Compt. Rend. Acad. Sci. Paris, CLX, pp. 920-1. Sot 8 NAIR sem sais bape a ee act | 1850 | Thélohan, Annal.de Microgr., II, pp. 198, 200-4, 207, 209, 210, pl.1, figs. 2, 3, 12-16. | x lervsrsletetera ate [ose eee eeee ' 1899 | Thélohan, Compt. Rend. Acad. Sci. Paris, CXI, | } p. 695. So esp assed eee scopes 1890 Pfeiffer, Arch. f. pathol. Anat. u. Physiol., CX XII, | | pp. 558-9, 563. Se sae eee nen Naess 1890 | Pfeiffer, Die Protozoen als Krankheitserreger, 1 ed., pp. 44, 47, 48, figs. 14, 16 (part; all ?). Oats | eicceane eeeeta te 1891 | Pfeitier, Die Protozoen als Krankheitserreger, 2 ed., | pp. 130, 133-4, figs. 54, 56 (part; all 2). We aoe soti Myob- | 1892 | Thélohan, Bull. Soc. philomat. Paris, IV, p.177. | olus. pacecntges -.-do ....| 1893 | Gurley, Bull. U.S. Fish Com. for 1891, XI, p. 414. Sawai ote or '...do...-.| 1893 | Braun, Centralbl. f. Bakt. u. Parasitenkde, XV, | p. 739. et aciessck 2 ..-do..... 1894 | Braun, Centralbl. f. Bakt. u. Parasitenkde, XVI, | p. 87. Synonymy.—The number of known forms habitant on Tinea tinca is large and their relations inter se are dubious. By the separation of M. piriformis, Thélohan has made a decided advance in the direction of clearness. By its lanceolate shape, single capsule, and large capsular index it is distinguished clearly from MV. ellipsoides and from M. brachy- cystis. It is probable that some of Pfeiffer’s degenerated forms should receive a somewhat similar interpretation. His figures are, however, such that in the absence of more definite statements they can hardly be placed. One of them (pl. 21, fig. 3d) would seem to belong to this species. The others are entirely indeterminate. Cyst.—Thélohan (1890, p. 203) saw cysts enlarge, become submucous, distending the mucous membrane, which subsequently ruptured, per- mitting the cyst to shell out and fall into the water, where it burst exactly as with the subcutaneous cysts of Gasterosteus aculeatus. Cysts are found in the comparatively exposed parts, e. g., the subcutaneous and intermuscular connective tissue and in the subepithelial tissue of the branchi, being absent in the internal organs (air-bladder, ete.). Myxosporidium.2—(a) In the air bladder: Two forms occur in the air-bladder of the tench; the first very similar to that found in the 1See p. 211, footnote 1, and the explanations of the plates. 2?Thélohan, Annal. de Microgr., 1890, 11, pp. 201-2, 922 REPORT OF TIIE COMMISSIONER OF FISH AND FISHERIES. urinary bladder of Lucius lucius, consisting of small free masses lining the internal surface of the organ, the second consisting of drawn-out, chain-like masses in the midst of the tissues of the organ. The second he believes to be merely a more advanced stage of the first. When the parasite is only slightly developed its presence is recognizable only by small opaque streaks in the otherwise transparent bladder, on opening which the myxosporidium is found upon its internal surface. In other cases small white prominences are found, presenting a transition between the large mammillated masses described by Balbiani, and which can attain 10mm.in thickness. Sections showthe myxosporidium intimately united to the epithelium. The latter soon becomes broken up and the plasmic chains insinuate themselves between the fibers of the connec- tive tissue. By serial sections one can follow progressively the march of the para- site into the tissues. These last allow of separation and stretching of the fascie, such change being progressive and slow. Soon, however, under the continuous pressure produced by the growth of the invading mass, the fibers arrive at the limit of extensibility and finally rupture. Thus are formed irregular spaces, in the middle of which one finds the débris of the tissue of the organ, surrounded by the myxosporidia. During this time spores are formed. They finally almost entirely replace the protoplasm. In other parts of the same mass earlier and intermediate stages can be seen. In the air bladder, as in the kidney, the distinction between the ectoplasm and endoplasm is little evident and, beyond the fact of the absence of nuclei from the ectoplasm, it is difficult to find characters to separate these layers. (b) Of the external surface, Balbiani' gives, as the results of his investigations, the following account of the development: Of all freshwater fishes the tench is most frequently affected with Myzxosporidia and at all seasons. This, together with the transparency of the fins of the young, renders it especially favorable for investigation. Balbiani frequently observed upon the fins, mingled with developed psorosperms, small amcsboid bodies of very variable size. These move like the most agile amebe (e. g., A. diffluens), 9 changes of form occurring in less than 15 minutes; temperature had great influence, heat accelerating, cold retarding. The pseudopodia were large and obtuse, the mass appearing lobed, as in 4. diffluens. Unless obscured by fat globules (numerous in the later stages), the nucleus is plainly visible, particularly at the time of the exit of the mass from the spore. It is the nucleus of which Biitschli has proven the existence in the interior of the psorosperm (cf. p, 208). There is no contractile vacuole, and from this point of view these bodies differ from the ordinary amebee. While thus wandering over the fins, the small ameboid bodies absorb nutriment, grow, show more or fewer fatty globules, tend to take a rounded oval, or sometimes irregular form with expansions and lobes, and to surround themselves with a thin envelope easily visiblein water. As the water penetrates the fin tissue, the ameeboid movements become more and more slow and finally cease. Independently of its thin proper membrane, the small mass is encysted in the same manner as other foreign bodies, by the connective tissue of the host. 1 Journ, de Microgr., 1883, vu, pp. 2724. THE MYXOSPORIDIA, OR PSOROSPERMS OF FISHES. 223 Spore formation.—With the growth the number of nuclei increases by successive divisions! (many of which were seen to occur). Subsequently each nucleus con- denses around it some of the myxoplasm, thus forming the pansporoblasts. These grow, become elliptic, and the rudiments of the capsules appear in them, at first as very pale, then as brilliant bodies. The mode of their development was not entirely satisfactorily ascertained. They usually develop 2 in each pansporoblast, some of these sporoblasts containing 3 granular globules, 2 small and 1 large, which prob- ably develop respectively into the capsulesand the sporoplasm. Also incompletely developed spores were seen inclosing elements believed to be capsules in process of development. These were: (1) Two spherical vesicles containing each a small cen- tral globule placed in the substance of the spore remote from the poles. (2) Two small similar vesicles placed one beside the other at one pole. (3) Two pyriform vesicles with a small central globule, sometimes remote from each other, sometimes approximated to each other and situated at one extremity of the spore. These vesi- cles were ne doubt the small organs with spiral filaments. Their origin could not be clearly determined. Spore.—F lattened-ellipsoid, rather elongate, the two ends similar; length 12 to 15 41; breadth 9 to 11 «3 length of capsules 4 4“; nuclei of capsulogenous membrane persisting to maturity of spore; vacuole present; nuclei originating by continued division from a primitive one, not more than 4; when of this number, 2 are situated before and 2 behind the vacuole (Thélohan, pp. 209-210). Degenerate forms [of this species ?] from the gall bladder may have 3 capsules or none, and the bivalve character of the shell may be absent (Pfeiffer). Ribbons: Balbiani” has made some curious but dubious observations, arriving at conclusions which by no means accord with the general consensus of opinion. He describes an elastic, ribbon-like process (the ribbon) as existing along the border of each valve of the shell, stating that at the time of maturity of the spore (the only period at which such ribbons are visible, as at other periods they are closely appressed to the valves) they become unrolled and recurved, such action resulting in the splitting apart of the valves and the consequent release of the amceboid sporoplasm. The ribbons divide at their distal extremity into 2 or 3 ribbonettes. These elastic structures he regards as comparable to the cruciform elastic filaments (elaters) of the Equise- tum spore, remarking that in the Myxosporidia they serve a different function, their action here being valve-separation and not spore-disper- sal. He further says that these elastic ribbons have another function, viz, to maintain contact of 2 spores during what he regards as astate of From -Balbiani’s language it is plain that he did not recognize the vacuolic nature of Biitschli’s ‘‘nucleus.” Still he must have seen nuclei (and not vacuoles) in the later myxosporidium stages, as he states that he repeatedly observed them to divide. Probably Thélohan’s observation of karyokinetic division (Compt. Rend. ’ Acad. Sci. Paris, 1890, cx1, p. 693) was upon WM. ellipsoides, though it isnot distinctly so stated. Among other figures he saw a spindle with an absolutely typical equa- torial plate. 2Journ.de Microgr., 1883, vu, pp. 276-7: Légons sur les Sporozoaires, 1884, pp: 1424, 994 REPORT OF THE COMMISSIONER OF FISH AND FISHERIES. conjugation. And still further, in some individuals the filaments instead of lying along the borders ofthe valves, extend themselves in the direction of the axis of the body, and, reuniting themselves for a variable distance, conmitute the simple or double caudal prolongation that Miiller and other observers describe as a specific character of certain psorosperms. (See also p. 207.) Concerning these, Biitschli! states that he could find no evidence whatever of the existence of such ribbons, either in the whole spore or in the separated valves. He seems to think that such ribbons are an illusion due to an abnormal extrusion of the capsular filaments. Thélohan’s observations seem to throw some light upon this diserep- ancy. This observer? says that he has never seen them except in the present species. They are frequently absent, yet the spores split open perfectly. Having found all possible transitions between the ribboned spores and spores evidently monstrous and abnormal, he regards the ribbons as structures, accidental rather than fundamental and neces- sary to the development of the spore. Habditat.—Thélohan gives this as the branchiz, air bladder, liver, intestine, and spleen (last fide letter to author, 1893) of Tinea tinea L. (tench). Balbiani says the Myxosporidia are always confined to the short anterior portion of the air bladder. Speaking collectively of a poorly delineated and very probably multi. specific group of forms, Pfeiffer says that perfectly developed forms occur on the branchie and in the air bladder, this stage of development being possibly connected with an abundance of oxygen. In the gall bladder incompletely developed forms occur, with 3, 1, or no capsules; also entirely undeveloped forms, destitute of a bivalve shell, compara- ble to the Microsporidia or to the pseudo-navicelizw found in Lumbricus. Transition forms to the Coccidia also occur. Possibly (from Pfeiffer’s figure) M. ellipsoides may also occur in the air bladder or gall bladder. Effects —The Myxosporidia do not confine themselves to existing cavities. Thus, in the kidney of Tinca tinca, Thélohan (1890, p. 200) has seen the tissue of the organ invaded while the tubes remained free (see also the above description of changes produced in the structure of the air bladder by the myxosporidium found in that organ). 50. Myxobolus ? sp.incert. Pl. 22, fig. 4. Psorosperms of Cyprinus leuciscus, Miiller, 1841, Miiller’s Archiv., p. 486; %b., Dujardin, 1845, Hist. Nat. des Helminthes, p. 644; ib., Leuckart, 1852, Archiv. f. physiol. Heilkde, x1, p. 436, fig. 2le, d; ib., Robin, 1853, Hist. Nat. des Végét. Parasites, p. 299. Synonymy.—This is little more than a collection of references to spores found on “Cyprinus leuciscus.” Robin’s mention is, however, certainly the same as Miiller’s. Cyst and myxosporidium unknown. 1Ztschr. f. wiss. Zool., 1881, xxxv, p. 633; Bronn’s Thier—Reich, 1882, 1, p. 598. 2Compt Rend, Acad. Sci. Paris, 1889, c1x, pp. 920-1, . THE MYXOSPORIDIA, OR PSOROSPERMS OF FISHES. 225 Spore.—Resembling Chloromyxum dujardini; 11 yp (0-0051/”) long and 7 u (0-:0034/”) broad. Habitat.—On Leuciscus (Squalius) grislagine L. (= Cyprinus leuciscus). Tumors less common than on Leuciscus rutilus. It seems strange that Miiller should approximate this form to the “sharp corpuscles of C. rutilus,”! as Leuckart’s figure resembles much more closely the elliptic form figured by Miiller (Miiller’s figs. f, g; pl. 28, figs. 5f, 9). 51. Myxobolus sp. incert. Pl. 22, figs. 5, 6; pls. 23-25. Barbel | ‘psorosperms,”} miulleri.* | Date. Authority; reference. etc., of— | 3S 00S AA RES aoSattmoade 1885 | Mégnin, Bull. Soc. Zool. France, X, pp. 351-2 (fig.); Compt. Rend. hebdom. Soc. Biol. Paris, II, pp. 446-7. Se he PE Rhee tt SoS 1886 | Railliet, Bull. et Mém. Soc. Centrale Méd. Veter. Paris, IV, pp. 134-7. eB TORE BCeSEpe Myxobelust| 1889 | Ludwig, Jahresber. rhein. Fisch.-Ver. Bonn, 1888, (pars). pp. 27-36. ° 3S tag hewowee ses cgse | 1890 | Railliet, Bull. Soc. Central. d’Aquicult. Paris, IT, pp. 117-20. ME |Recaccesesce 4s 1890 | Pfeiffer, Virchow’s Archiv. f. patho]. Anat. u.Physiol., CXXII, pp. 552, 557-8, pl. 12, figs. A2, C1-8. etre il crise al ccc 1890 | Die Protozoen als Krankheitserreger, 1 ed., pp. 28-9, 55, 67, fig. 10, plate, figs. IV, V. Ker ah \\oeeeacec sos < 1891 | Pfeiffer, Die Protozoen als Krankheitserreger, 2 ed., pp. 100, 105-10, 180, figs. 48b, 45, 57. x | Ssocecsecease 1892 | Thélohan, Bull. Soc. philomat. Paris, IV, pp. 168, 178. x oocotetssenced 1892 | Henneguy and Thélohan, Annal. de Microgr.,IV, p. 619. ca nage Breet ee ane 1893 | Thélohan, Compt. Rend. hebdom. Soc. Biol. Paris, V, pp. 267-70. SrA Beegect | AED ps Stee 1893 Pfeifler, Centralbl. f. Bakt. u. Parasitenkde, XTV, pp. 118-130, plate, figs. 13-15, 16 (pars). We eas Eo eS ee 1893 Sticker, Archiy f. Animal. Nahrungsmittelkde Wien, | VIII, p. 124. IMtyXODOIUS. p= eel niniae == 1 1893 | Railliet, Traité de Zool. Méd. et Agric., pp. 158-159. * Non Biitschli. + Ludwig’s figures seem as though they might be generalized composites based upon several of Biitschli's. They may thus perhaps be not independent figures of the spore habitant in the skin of B. barbus, but have been considered to represent that form in view of its supposed identity with I. miilleri, Synonymy.—Both Mégnin and Ludwig, the former with doubt, the latter apparently without hesitation, regard this form as identical with M. miilleri. While admitting their superior advantages (of direct . observation of material) I still feel considerable doubt as to the iden- tity of these 2 forms, and have therefore provisionally classed them separately, as, while I do not consider that there is sufficient ground for a positive assertion of the distinctness of the two forms, there is certainly sufficient to justify a hesitation as to their fusion. Mégnin says the present species is probably the same as that described by Robin and Balbiani as infesting the tench and carp. Now as to this: (1) I am not aware that Robin ever observed such a form, and (2) the spore habitant on the tench (M. ellipsoides) is, as shown by Thélohan,? unquestionably distinct from that habitant on the carp (M. oviformis), 1 “Bei C. leuciscus glichen sie ganz den spitzen Kérperchen des C, rutilus,” 2 Annal. de Microgr., 1890, 11, p. 210, FO 15 , 926 REPORT OF THE COMMISSIONER OF FISH AND FISHERIES. Further, Mégnin’s figures would not by themselves induce me to fuse the two forms. Besides, after considerable study of Ludwig's description, I am unable to decide how much of it represents his own observations and how much is copy of Biitschli’s description of M. miillert. It seems to be part original and part copy, but how much of each it is impossible to determine. It would seem as though Ludwig first determined in his own mind the specific identity of the present form (J. sp. 51) with M. miillert and then applied to the former (M. sp.51) Biit8chli’s description of M. miilleri, at the same time incorporating therewith certain observations, e. g., the dimensions of the spore which must be his own (made upon A. sp. 51) inasmuch as they are not, tomy knowledge, to be found in any previous description of M. miilleri. My reason for this view of the subject is Ludwig’s statement that— I ean only confirm Biitschli’s results upon the finer structure of M/yxobelus. Further, his figures bear some indication of being semidiagrammatic generalized composites of several of Biitschii’s figures of M. miilleri. And still further his description (except the few additions) is Biitschli’s. This course has rendered it impossible for me to distinguish how much of the composite description represents Ludwig’s actual observations on M.sp.51 and how much of it merely pertains to M. miilleri generally, and is regarded as applying to M. sp. 51, by virtue of its supposed identity with M. miilleri. Under these circumstances I have credited to M. sp. 51 only the minimum (viz, the residual after subtracting from the composite, Biitschli’s description of M. miillert); as, though this residual may be incomplete for WM. sp. 51, it is all that can be positively asserted to belong to that species. Pfeiffer’s figures (pl. 25, figs. 5,6) approximate the present form much more closely to M. ellipsoides than to M. miilleri. Finally, Thélohan says that the present species— Presents a great resemblance to M. miilleri; perhaps it should, however, be con- sidered as specifically distinct. Cyst.—Membrane thin, probably formed by host. Contents clear living protoplasm, in which are imbedded very fine dark granules, very small nuclei corresponding to those of true cells, and spores (Ludwig), Composed of an irregularly concentric-fibered layer inclosing a second double-contoured layer, which latter surrounds the cyst cavity filled with spores. The large white, stout-walled, walnut-sized, or smaller muscle cysts are situated near the skin or pleura; 30, 40, or more myxosporidia occur near together, surrounded by a loose web formed by the host. Each myxosporidium is to be regarded as an individual, and the multicamerate tubes result from the common encap- suling by the host of many such individuals of nearly equal age, which individuals subsequently, he thinks (from sarcosporidian analogy, etc.) fuse, the process recalling the so-called conjugation of the large free- living intestinal Gregarines (Pfeiffer). THE MYXOSPORIDIA, OR PSOROSPERMS OF FISHES. 227 Myxosporidium.i—P feiffer has seen the exit of the sporoplasm. He did not have the opportunity to cultivate the spores via the over- hanging drop, but says such cultivation would be easy and would show the stage at which infection occurs. He did not actually see the myxosporidium penetrate the muscle cell, but he has found within that cell all growth-stages of the myxosporidium. The elongate myxo- sporidia often show, in their center, pansporoblasts containing well- developed spores, while at the ends these structures are smaller and contain only 1, 2, 4, or more nuclei. This proves that, as in the Sarco- sporidia (also with the tubes of Sygnathus and, fide Thélohan, with those of Cottus scorpio), growth takes place at the ends of the tubes. Have these younger developmental stages originated from germs from the interior of the large tube, do they proceed from residual germs of the first multiple infection, or do they develop from newly immigrated germs? A positive answer can not yet be given, but inthe barbel Pfeiffer regards the second mode (viz, a supplementary outgrowth from the germs which penetrated en masse in the first infection) as the more probable. In the myxosporidium tubes germs migrate from the center to the circumference, where they find better food conditions and through progressive division become new pansporoblasts (Sporenkugeln). The center of the cyst is also empty in the cysts of the sheep, those of the tench’s air bladder, and that of the kangaroo’s intestine. When the myxosporidia have attained a certain size, they are found free in the interstices of the muscular fiber. When crowded, they fuse to an irregular mass; only at the edges are some unfused myxosporidia to be seen. Hzematoidin crystals are found in the myxosporidium. Spore formation.—This appears in the smallest cireular cysts with 16 to 20 germs; also in uniloculate elongate cysts thickly filled with 100 to 200 germs. In places large granule cells are imbedded in the musecu- lar fiber. At another (?later) stage the dancing granules have vanished and the contents of the cells have separated with 10 to 20 or more pale globules one-third the size of the ripe germs. Also some fibrilla show in their interior well-developed spores, with capsules and nuclei, single or in rank and file (? accident; ? pressure on cover-glass). The possi- bility of these must be admitted, yet the contents of the capsules appeared to have been voided. Spore.—Lenticular or oval; length 12 yz, breadth 10 , thickness 6 su (Ludwig); bivalve, shell cavity containing sporoplasm and 2 capsules, the latter extruding filaments under the influence of potassium hydrate (Mégnin); by glycerin (Pfeiffer). Have the Myxosporidia resting spores?) Mega-, and micro-spores (differing only in size) occur; also defective spores with 1 capsule, with caudiform appendages, or with a subrotund form (Pfeiffer). Habitat.—Eneysted and free in muscles, mostly of belly and sides of body (never elsewhere, the liver, spleen, ovary, eggs, and gills being ' Description, Pfeiffer’s (loc. cit., 2 ed., 1891, p. 106). 928 REPORT OF THE COMMISSIONER OF FISH AND FISHERIES. free) of Barbus barbus L. (barbel) from the Rhine, Mosel, and Saar, the barbels of the Elbe and Weser territory being free from them (Pfeiffer). Also once in heart cavity (Ludwig). In barbels from the Marne, probably also from the Aisne and Seine (Railliet). Balbiani failed to find “adult psorosperms” in the viscera in Mégnin’s material (Mégnin). Liver, kidney, spleen, connective tissue of various organs; found in ovary by Balbiani.! In one case the myxosporidia and spores were lodged in a sort of cavity in the connective tissue of the intestinal wall 10 em. from the anus. They produced a very conspicuous thickening, almost completely obliterating the lumen. Pathology—Tumors:? A badly infected barbel showed about 40 tumors; fully 10 per cent of all the muscular fibers were filled with spores. This condition must have resulted from auto-infection. The tumors may soften to an irregular stinking abscess containing spores, wandering cells, and the large bacilli (Pfeiffer; see below under Ulcers). Tumors, usually 10 to 15, ranging in size from a nut to a hen’s egg, with avery resistant wall 1 to 1:5 mm. thick; hemispherical or slightly elongate; sometimes uniting into patches 17 to 20 mm. long by 7 or 8 mm. broad in fishes of 2°5 kilos (about 5 pounds) weight. Seales over tumor raised, easily detachable, finally falling off. Not all tumors open, some fishes dying before the ulcer stage. Some fishes die without external tumors, these being found located in the viscera (Meuse; Railliet). Uusually of walnut size; sometimes, however, 50 mm. long and 20 mm. thick, single or multiple, usually on belly or sides; filled with a yellow or caseous purulent mass (Mosel, Saar; fide Ludwig). 1 Fide Thélohan (Annal. de Microgr., 1850, 1, p. 200; Compt. Rend. hebdom. Soe. Biol. Paris, 1893, v, p. 268) who refers to Balbiani’s Légons sur ler Sporozoaires. The only page of the last work to which the reference could apply is p. 147, and as M. Thélo-_ han says (letter to author, 1893), Balbiani is there not at all explicit, 2The following notes of four cases are from Ludwig. The fish were taken alive from the Mosel above Trier, died en route, and were examined the next day: 1. ¢ 30cm. long; on left side just above ventral fin a tumor 50 mm. long, 40 mm. broad, and 30 mm. thick, extending above lateral line; skin and omentum in neigh- borhood of tumor normal. 2. 9 47cm. long; two tumors: (a) on right side above ventral fin, under trunk muscles (which latter were, around the tumor, reddened), 45 mm. long, 35 mm. broad, and 15 mm. thick; covered by normal skin. Tumor so extended into body cavity as to have driven the omentum hernia-like before it. (b) On left side in front of pelvic bone, length 50 min., breadth 15 mm.; already opened; orifice 10 mm. in diameter with an irregular strongly reddened border, surrounded by reddened skin. Cavity of ulcer filled wish bloody mneus, which, apart from the admixture ofblood, agreed with the tumor contents. 3. 9 44cm. long; on left side at level of lateral line, between ventral and anal fins, a tumor 25 mm. long, 12 mm. broad, and 12 mm. thick; heart cavity filled with same substance as tumor contents. 4. g 30cm. long; in front of left ventral fin a tumor 35 mm. long, 25 mm. broad, and 25 mm. thick, projecting but little externally, but greatly into abdominal cavity. THE MYXOSPORIDIA, OR PSOROSPERMS OF FISHES. 229 Opening of the tumors: The active agents in the puriform transfor- mation and opening of the tumor are the bacilli first observed by Pfeif- fer in the ulcer contents. These are only found in the myxosporidian- infected muscles, never in other organs. The presence of these microbes either prevents connective tissue proliferation entirely, or prevents it from becoming complete, the tissue undergoing gangrene (a digestion- liquefaction, so to speak), which soon results in the destruction of the overlying tissues. Subsequently the bacilli were studied by Thélohan (see synonymy, 1893) who observed two kinds of them: 1. Bacilli: Large, motile, as long as the spores, showing with hematoxylin 4 or 5 red granules, and a short flagellum; frequently several cohere by their surfaces; also long separated threads occur (Pfeiffer, 1891, p. 105). Length 6 4; sometimes isolated, sometimes in linear colonies, no motion seen; rap- idly liquefying gelatin upon which it gives large, slightly yellowish-white colonies; in rabbits provoking a small, very limited abscess; staining easily with methylen blue, gentian violet, fuchsin, etc. (Thélohan, 1893). 2. Cocci: More rarely, sometimes with last, sometimes alone, another species consisting of Cocci isolated or united under the form of Streptococci or Diplococei occurs. Ulcers: The tumors subsequently soften and burst, forming deep crateriform bloody-bordered ulcers filied with a yellowish purulent mass consisting of spores and of cell detritus. Among the latter large bacilli crawl. Cell intection: The primary seat of infection is the interior of the muscle cell. Myxosporidia are found within well-preserved (distinctly transverse-striate) or markedly atrophied muscular fibrille; also be- tween healthy fibrille. Atrophied muscle-cells are seen containing long rows of well-developed spores, which, on account of the absence of filaments within the capsules, Pfeiffer inclines to believe have reached their present position by a general immigration. In places the fibrille are beaded, such muscle bead-strings being ordinarily heaped near together in the neighborhood of the hard cysts. Around the eysts the muscular tissue is infiltrated with blood, the infiltration, where super- ficial, being visible through the skin. Near the ulcers the muscular substance is broken up, loosened, fatty-degenerated, and contains blood- colored tubes with numerous myxosporidia not yet encapsuled and also well-developed spores. Thélohan! says: In the ovary they are very frequently encountered. M. Balbiani has studied them in the ovary of the barbel and he has seen that the psorospermic matter does not confine itself to traveling via the connective tissue, but often invades the young ovules. Pathological anatomy.?—The presence of the parasite in the primitive muscle fiber seems to lead rapidly to degeneration. On examining 1Annal. de Microgr., 1890, 11, p. 200. >Description Thélohan’s (Compt. Rend. hebdom. Soc. Biol. Paris, 1893, v, pp. 267-270). 230 REPORT OF THE COMMISSIONER OF FISH AND FISHERIES. fragments in the fresh state, fibers are seen, which, in places, have pre- served their normal aspect and their striation, and at other points more or less considerable spaces, where the muscular substance is filled with a vitreous refringent mass, around and in the intervals of which lie fatty droplets, yellowish granules, and spores. The degeneration invades gradually the muscular substance of the primitive fibers, and one finds it in parts of these elements, where the parasite appears not to have penetrated. On the contrary, the neighboring, noninfested, primitive fibers seem exempt from that alteration, and one frequently observes a degenerated fiber surrounded by healthy ones. The fiber thus degenerated and broken up, is soon invaded by pha- gocytal cells coming, some from the sarcolemma, others from the con- nective tissue. This latter, at the diseased points, is the seat of avery marked irritative proliferation. It is necessary to distinguish, in the degenerated fiber, the parts where spores are found in great number, and those where these elements are few or absent, the degenerative process in the latter case having originated from the presence of the parasite at a different point. In this latter case the cells which have penetrated into the degen- erated tissue multiply rapidly; in proportion as their number augments, one sees the muscular débris diminish; very soon they have completely disappeared, the place of the fiber being finally occupied by connective tissue. While these phenomena occur, the irritation is propagated, the connective-tissue proliferation extends itself, and a sclerosis of the neighboring muscle region, with atrophy of the primitive fibers, is pro- duced. At the points where the degenerated fiber incloses a great number of spores, the formation of connective tissue is at first limited to a thickening of the perimysium. There are thus formed connective-tissue bridges, separating the spaces occupied by the spores, and which correspond to disappeared primitive fibers. These facts are seen especially clearly on transverse sections. Little by little these bridges increase in thickness, at the same time their tissue becomes more dense; they thus form around each space a fibrous shell, which tends to con- tract more and more. There seems to be here a true encystment of the parasite, such as is produced around foreign bodies introduced into the tissues. Symptoms.—Barbels attacked are less lively than usual and have much difficulty in ascending streams; surface of body, dull, grayish yellow, oily, slippery (Meuse; Railliet). Less lively than usual, easily caught in the hand, breasting the ecur- rent with difficulty, avoiding rapid water (their usual haunt), taken in great numbers in bow-nets. Some affirm, others deny, that the sick fish will not bite at the hook. Diseased fish are of all sizes. Those seriously affected are of a weight much below that indicated by their external appearance, the body being in fact more or less dilated. On — «eee THE MYXOSPORIDIA, OR PSOROSPERMS OF FISHES. 231 this account the fishermen often estimate the weight at nearly double the actual (Railliet.) According to Vet. Surg. Hanzo, the affected fishes float on the surface as though poisoned with Cocculus indicus. EHpidemics.—In the Meuse it has manifested itself with the characters of a veritable epidemic during three consecutive years, from 1883 to 1885, inclusive. It became progressively more aggravated, reaching its maximum of intensity towards the middle of 1885. On certain days of that year M. Ladague had interred nearly 100 kilograms of barbels; the Meuse was covered with dead fish. The disease subsided little by little, and actually appeared to become extinct, but it could almost be said that the combat closed for want of combatants. In the district of Ardennes it was remarked only in the Meuse itself; all the affluents have always been spared. The maximum intensity, according to Railliet, was reached about the middle of 1884. On certain days, at Méziéres alone, as many as 100 kilos (about 200 pounds) were interred. Some years later the disease had disappeared from that region, but raged down stream at Monthermé and Givet. In the neighborhood of Nancy the barbels die in great numbers (Mégnin). In the Aisne Railliet was informed of ravages of the disease occur- ring near Rethel. The disease, he thinks, extended to the Aisne and the Marne from the Moselle via the canals. In the Marne a considerable number of barbels floated dead or unable to escape, down the lower Marne. The disease appears to have begun (at least in the neighborhood of Charenton) about June 15; thence it progressively increased, attaining its maximum at the time of emptying of the St. Maurice Canal. It persisted till the end of July, at which date Railliet’s information ceased. In the Seine it did not extend above the Port a VAnglais dam. The Grenelle fishermen, Railliet was informed, had seen a great number of sick barbels. The Seine thus appears invaded, without doubt consecu- tively, from the Marne. In the Rhine and its tributaries, the Saar and Mosel, according to Ludwig, it seems tu have appeared at least several decades ago without, however, ever having attained the magnitude that it has reached in late years in the Mosel. The disease has there been observed since the end of 1870 and has so increased that, especially in the warm summer months, the dying and dead fish from the upper Mosel and Saar pass Trier by the hundreds, and at Zell (on the Mosel) it is reported that they spread a carrion-like odor. According to Pfeiffer, in the Saar and Mosel during the summer of 1890 no very extensive mortality occurred. Contributory causes.— AS regards age as a predisposing factor, Railliet observes that in the Meuse the young barbels are attacked as well as the old, the weights of dead fish varying from 22 grams to 6 or 7 kilograms. 232 REPORT OF THE COMMISSIONER OF FISH AND FISHERIES. In the 3 German streams Treplin! believes 3 series of cases to be dis- tinguishable: (1) Mostly small fish (up to100 grams), still well nourished, with only individual, or without recognizable, indurated patches, and which present in the abdominal region, at most, 1 hard tumor. (2) Somewhat larger fish (up to 200 grams), which Hee: always show in several places on their sides hard, somewhat swollen, patches; also tumors similar to those on the smaller fishes, mostly on the abdominal region. These fishes already begin to emaciate. (3) Fishes of and above the preceding weights, showing on the sides, belly, or back large ulcers, mostly lying immediately under the skin. A part of the same is already broken up; borders foul and red; interior containing a yellow pus. The fishes have emaciated greatly, and die. Season, Railliet thinks, appears to have no influence, fish being seen dead in midwinter as well as in June, July, and August. Pollution of streams Railliet considers a minor factor, saying: The diversion into the Meuse of manufactory refuse is often blamed for the existence of this condition of affairs, but the investigations of M. Ladague tend to incriminate rather the erection of dams at certain points on the river, these structures diminish- ing the rapidity of current, in the midst of which the barbel ordinarily lives. Treplin' believed that the young barbels receive the germ from refuse deposits of industrial establishments (breweries, malt houses, tanneries, distilleries, etc.) on the headwater of the Saar and Mosel; and, further, that these germs enter by the alimentary canal, passing thence into the rest of the body, and first make their exit therefrom (via the ulcers) in the second or third year. Herr Hanzo,? on the contrary, considers the cloth and paper mills as chiefly responsible, as these establishments handle old rags which are, he says, saturated with infective material. Of the views of Treplin and Hanzo, Ludwig considers that of Treplin to have the greater degree of probability. Both, however, he remarks, consist only of opinions and probabilities, and further leave out of sight other sources of contamination. While no sufficient evidence exists for holding pollution of water by different industrial establishments respon- sible for barbel myxosporidiosis, an indirect connection between such water pollution and the disease is by no means to be entirely rejected. It is very easily possible that such pollution may favor myxosporidian increase and development, and especially that it may, by injuriously affecting the general life conditions, diminish the normal resistive power of the fish, thus rendering infection more easy. This view ex- plains the fact (fide the fishermen) that the barbels at Bonn recover, while they die in the Saar and Mosel, in which latter streams pollution inust, on account of the smaller volume of water, affect the fish more injuriously. M. Braun? places less stress upon fouling of the water, as once Av ha Td wie, Tepeeeier. ae Fisch.-Vereins, Bonn, 1888, p. 34. 2In Ludwig, loc. cit., pp. 34, 35. 3 Review of Ludwig in Centralbl. f. Bakt. u. Parasitenkde, 1889, v, p. 420. THE MYXOSPORIDIA, OR PSOROSPERMS OF FISHES. 233 healthy whitefish sickened from introduction into water in which a whitefish affected with myxosporidiosis had died, and as the same dis- ease is not rare upon Coregonus from lakes. Peipus and Ladoga. Heciting causes —This may be safely assumed to be the presence and development of the myxosporidia. Pfeiffer,' from numerous exami- nations, states that these latter are always present in barbels from the Rhine, Mosel, and Saar, becoming pathogenic only at irregular inter- vals, probably when other causes so diminish fish vitality that the reactive encapsuling of the parasite is no longer possible. The latter then obtains the supremacy, and through the accompanying bacteria rapid death of the fish may result. Mégnin’s opinion is as follows: Mode of infection.—One now understands how the fish become infected; the psoro- sperms which escape from the ulcers are ingested with the water during deglutition or respiration; under the form of an amcboid they enter the circulatory current, then arrive in the subcutaneous cellular tissue, which is their seat of election, where they undergo their last transformations. Upon this subject Ludwig remarks that— The greater frequency of occurrence upon the branchiw suggests that infection occurs less through the alimentary canal than through the respiratory tract. The lymph paths of the connective tissue appear to represent the principal channels by which the parasite spreads through the body, but nothing certain is known.? The infection of previously healthy fishes is brought about, Pfeiffer remarks, through the extensive fouling of the water by the numerous fish corpses, and the durable construction of the spores. Infection may then take place via the stomach, gills, or wounds. The last are of fre- quent occurrence in the spring at the time of breaking up of the ice. Remedies proposed.‘ How, now, to arrest the epidemic? It is diffi- cult. Isee no other method than to collect all the dead or sick fishes and destroy them by fire” (Mégnin). Ludwig thinks that our ignorance of the complete life-history of the parasite, and especially of the way in which it secures a lodgment in the fish, precludes rational radical measures and permits us only to adopt certain prophylactic makeshifts. With reference to myxospo- ridiosis, as also for a number of other reasons, the waters, especially the Saar and Mosel, should be maintained in the highest state of purity, and to that end all pollution of the rivers mentioned, by communities or industrial establishments, should be interdicted. ‘That most dan- gerous contamination of the water, by the Myzosporidia from the ulcers, cannot, of course, be stopped entirely, but it is evident that it will be less if all fishermen are impressed with the importance of destroying? all diseased and dead fish, instead of throwing them back into the water. Such destruction must be so effected as to prevent the reéntry of the germs into the water. 1 Die Protozoen als Krankheitserreger, 1890, 1 ed., p. 67; 2 ed., 1891, p. 110. 2No actual observations are cited in support of this lymph-path theory. 3 Pfeiffer (loc. cit., 1 ed., 1890, p.37) quotes Ludwig as recommending that they be buried. 234 REPORT OF THE COMMISSIONER OF FISH AND FISHERIES. Railliet (loc. cit., 1890) further says that every one up to the present appears to bein accord as to the means of combating the disease. It is, above all, expedient to collect the diseased fish and to bury them at a certain depth and at a great distance from the water course. This is what was done on the Meuse and one has just seen that this course succeeded sufficiently well. Thus at the end of some years the disease appears to have left no traces. Thus Railliet saw taken, even at Méziéres, 3 barbels, the smallest of which weighed 1:5 kilos or 3 pounds. Pfeiffer! says that prophylaxis must obviously be directed to the careful removal of all fishes dead of the disease. They should be burned or buried with caustic alkali. By this means, perhaps, the extermination of the barbel may yet be prevented. The only attempts at cure are cited by Railliet, who says that M. Ladague succeeded by opening the tumors in greatly prolonging the life of the fish, and sometimes in curing it. If, on the contrary, the disease is allowed to take its course the tumors increase rapidly and the fish soon dies. 52. Myxobolus? sp. incert. Pl. 26, fig. 1. ~ Psorosperms of Cyprinus erythrophthalmus, Remak, 1852, Miiller’s Archiv., pp. 144, 149, pl. 5, fig. 9B. Spore.—Tailed and untailed were seen. Habitat—From pigment follicles on wall of splenic artery of Leuciscus (Scardinius) erythrophthalmus L. Remarks.—As the relation between this form and Chloromyxum dujardini is at present doubtful, the present form is provisionally left separate. : 53. Myxobolus sp. incert. Pl. 26, fig. 2. Globules of Cyprinus phoxinus Rayer, 1843, Rayer’s Archiv. de Méd. comp., I, pp. 58-9, pl. 9, fig. 13. Cysts.—In the single specimen observed, 2 in number, yellowish white, the size of a pin’s head; contents, a mass of ovoid spores. Ether rendered the cyst contents more transparent, ammonia more cloudy. Myxosporidium and spore unknown. Habitat.—Encysted on left side of head of Phoxinus phoxinus L., from - the Seule River. Disease apparently rare. 54. Myxobolus oblongus Gurley, 1893. Pl. 26, figs. 3-6. (Psorosperms of Catostomus tuberculatus (Le Sueur), Miiller, 1841, Miiller’s Archiv., pp. 487-90, pl. 16, figs. 7-9; ib., Miiller, 1843, Rayer’s Archiv. de Méd. comp., I, p. 229, pl. 9, figs. 7-9; ib., Robin, 1853, Hist. Nat. d. Végét. Parasites, p. 301, pl. 14, figs. 9, 10.) Myxobolus oblongus, Bull. U. 8. Fish Com. for 1891, x1, p. 414; ib. Braun, 1894, Centralbl. f. Bakt. u. Parasitenkde, xv, p. 87. Myxosporidium unknown. Cyst.—Round or elliptic, not over 1 mm. in diameter; membrane 1 Die Protozoen als Krankheitserreger, 2 ed., 1891, p. 110. THE MYXOSPORIDIA, OR PSOROSPERMS OF FISHES. 235 resistant; contents whitish, consisting of spores, with more or less granular detritus. Spore.—Outline spatular, approaching roundish-oblong; untailed; length 14 to 17 yw, breadth 8°5 py, thickness 5 to 6 yu. Shell substance thin, almost perfectly transparent, insoluble in cold and moderately warm concentrated sulphuric acid, quickly destroyed when heated with the concentrated acid to near its boiling point; insoluble in concentrated solution of caustic potash, cold or hot. Valves separating in sulphuric acid (cold, concentrated), equally con- vex, the spore on transverse view appearing symmetrical ou both (superior and inferior) sides of the wide ridge. Greatest convexity of valves well forward (at about the junction of the anterior with the second fourth of the length;) ridge index nearly 4. Capsules 2, pyriform, of equal size, containing a coiled filament visi- ble (in iodine water) through the capsular walls; capsules drawn out anteriorly into the ducts, orifice visible. Methyl-green stains the capsular walls bright green; the filaments, sporoplasm, and shell not -atall. Under this treatment there are differentiated in the uniformly bright green capsular walls several dark green granules. Sometimes only 2 are seen, and these are then often situated approximately in the long axis of the capsules. Other specimens are seen with 4 or 5, which are usually arranged without marked regularity, generally, however, being collected near the center. Their nature is problematical. Their presence, position, and numerical range appear to be constant. Sporoplasm: The outline was not accurately traced, but the results, obtained by staining, suggest that upon the superior surface it may perhaps extend to the anterior end of the shell; upon the inferior sur- face if only reaches the posterior ends of the capsules. Upon this view of the relations, the capsules would indent the inferior surface of the sporoplasm. 22-6 se: Galeus'spas.seo-— eee eee Mustelus levis ..... Galeus mustelus............- Smooth dog- fish. Sleygbbiremn Cann Fs Bepeeessece d[ss-oceSecsnoasearcnae Seylliorhinus canicula L ....| Large-spotted dogfish. DSC VU ee [bea as ase on ats eer Seylliorhinus sp-............- Scyllium stellare....! Seylliorhinus stellaris ....---. Prighimnusieee sass <1 o2, == Pristiurus melanostomus Bon Spinax vulgaris ..|-........... Acanthias vulgaris.) Squalus acanthias L..-....... Spiny dogfish. Siigiimnes Qureshi) Ie ops cen ssa Sscdoossoec ber eeeeeene Squatina squatina L..-...... Angel-fish. SUITE || Lo osdesepsasoneaporistc Squatina sp -.-.-...........- Torpedo narke.-.,.|------.---.- | Torpedo narce....-- Torpedo torpedo Gmel. -| Electric ray. Torpedo -. Torpedoysp! sJoae-e eee Torpedo marmorata [Raja batis |] -----]------------]----------- 2+ +2 ----02-| 0-2-2 es - -| Raja sp --| Skate. Raja clavata. sal MRajarclawataeccseece cess eeee Thornback. ALANS Sh IBS s159 702 5es5 a0 5eusesuc Dasyatis Spe-seeseess-acse ce Stingray. Myliobatis aquila...| Cephaleutherus aquila.....-- Eagle ray. * By an evident misprint (rinvenne instead of rinvenni; ‘‘he found” instead of ‘I found”’) Perugia (Boll. Scientif., Pavia, 1890, x11, p. 136) states that Leydig, instead of Perugia himself, found this form in the series of hosts examined by Perugia. +Mingazzini gives nothing but the generic name of the host. As there is nothing to indicate the identity of the species of hosts with those examined by the other authors, they are noted separately. + This species I regard as distinct (see p. 261). 95. Chloromyxum fluviatile Thélohan, 1892. PI. 39, fig. 4. Bull. Soc. philomat. Paris, Iv, pp. 173, 176, fig. 2; ib., Gurley, 1893, Bull. U.S. Fish Com. for 1891, x1, p. 418; ib., Braun, 1893, Centralbl. f. Bakt. u. Parasitenkde, xiv, pp. 738, 739; ib., Braun, 1894, Centralbl. f. Bakt. u. Para- sitenkde, Xv, p. 87. Cyst none. Myzxosporidium.—The ectoplasm emits lobed pseudopodie. Endo- plasm, when young, colorless; when older, yellow; color appearing not to be located in special spheres. Spore formation.— Number of spores formed in each myxosporidium indefinite. Spore.—Nearly regularly spherical; size about 5 to 74; shell bivalve; bearing small, often difficultly visible, spines; ridge present; capsules 4; sporoplasm nonvacuolate. Habitat.—Gall bladder of Leuciscus (Squalius) cephalus L. This species is apparently rather rare; seen only twice; it is nearly related to C. leydigtt (Thélohan). 96. Chloromyxum mucronatum Gurley, 1893. PI. 39, figs. 5, 6. (Psorosperm of Gadus lota Lieberkiihn, 1854, Miiller’s Archiv., pp. 352-3, 368, pl. 14, figs. 5,6; ib., Lieberkiihn, 1854, Bull. Acad. Roy. Belg., x x1, pt. 2, p. 22, name only; ib., Leuckart, 1879, Parasiten des Menschen, 2 ed., p. 248, fic. 99a; ib., Biitschli, 1882, Bronn’s Thier-Reich, I, pl. 38, fig.17; ib., Bal- biani, 1833, Journ. de Microgr., vu, pp. 201, 203, fig. 45; ib., Balbiani, 1884, Lécons sur les Sporozoaires, pp. 130, 133, fig. 41;1 ib., Leuckart, 1886, Para- sites of Man, 2 ed., p. 197, fig. 99a; ib., Koch, 1887, Encyklop. d. gesammt. Thierheilkde u. Thierzucht, rv, p. 94, fig. 668, 3.) Chloromyxum mucronatum, Bull. U.S. Fish. Com. for 1891, x1, p. 419; ib., Braun, 1894, Centralbl. f. Bakt. u. Parasitenkde, Xv, p. 87. 1 See also below, under C., elegans (p. 266). ee ee THE MYXOSPORIDIA, OR PSOROSPERMS OF FISHES. 265 Myxosporidium.—The largest attaining 75 py (,'5/’ Lieberktihn), the smallest the size of a blood corpuscle; spherical or ellipsoidal, more rarely irregular, membraneless, containing irregularly scattered fat-like globules. Spore formation.—Many myxosporidia appear destitute of fat gran- ules, but show a large number of structureless gelatinous globules; other myxosporidia show partly the same globules, partly similar ones of the same size containing 4 capsules whose apices are approximated. Many globules show only faint indications of such capsules. Sometimes 2 such globules occur inclosed within a common structureless mem- brane. Besides these, developed psorosperms occur, both individually ana in heaps, held together by a mucoid substance. Spore.—Sharp-contoured, subglobular, mucronate anteriorly; length ad max., 8 uw; capsules 4, converging anteriorly. Habitat.—Free in urinary bladder of Lota lota L. (ling). Found in about 20 per cent of the fishes examined. Remarks.—Lieberkiihn emphasizes the striking resemblance between this species and those described by Leydig from the gall-bladder of the Plagiostomes (Chloromyxum leydigit and C. incisum). He notes, how- ever, that C. mucronatum differs from Leydig’s forms in the absence of a membrane around the myxosporidium, and in the absence of the pan- sporoblastic vesicles (Leydig’s Tochterblase). From later researches it is easy to interpret Lieberkiihn’s results in harmony with those of Ley- dig, as the vesicle stage of the pansporoblast is merely a later stage of the gelatinous globules of the above description (see pp. 81, 286). SUBGEN. SPHAROSPORA Thélohan, 1892. _ Etymology not given. Bull. Soc. philomat. Paris, Iv, p. 175; Myxosoma et Mixosoma!, ibid., p.175; subgen. (including Myxosoma and Mixzosoma) of Chloromyxum, Gurley, 1893, Bull. U. S. Fish Com. for 1891, x1, pp. 411-412, 418-419; Spherospora et Myxosoma, Braun, 1893, Centralbl. f. Bakt. u. Parasitenkde, xIv, p. 739; ib., Braun, Centralbl. f. Bakt. u. Parasitenkde, xv, p. 87. Definition.—Bicapsulate Chloromyxa; type Chloromyxum (S.) elegans. Species.—The study which, through the kindness of Dr. Ohlmacher, I was able to make of C. (S.) ohlmachert enabled me to recognize 2 other species in the literature which should be referred to this sub- genus. The first is Balbiani’s spore of Acerina cernua, which I have named Mywxobolus perlatus. The median anterior and posterior mucro- nate projections and the median line shown in Balbiani’s figures, can be respectively interpreted only as the ends and the intervening portion of the ridge. In other words, the valve-junction plane is vertical. The appearances are identical with those shown by C. ohlmacheri. The second is Biitschli’s spore of the ovary of Lota lota. Though Biitschli’s figures represent it as bicapsulate it should be compared with C. mucro- natum. 1Type Mvrosoma dujardini. 266 REPORT OF THE COMMISSIONER OF FISH AND FISHERIES. 88. Chloromyxum (Spherospora) elegans Thélohan, 1892. Pl. 40, fig. 1. (Myxosporidian spores of Gasterosteus aculeatus and G. pungitius (pars), Thélo- han, 1890, Annal. de Microgr., 11, pp. 193, 200, 203, 209, pl. 1, fig. 1.) Spherospora elegans, Bull. Soc. philomat. Paris, tv, pp. 167, 175. Chloromyxum elegans, Gurley, 1893, Bull. U. 8. Fish Com. for 1891, x1, p. 419. Spherospora elegans, Braun, 1893, Centralbl. Bakt. u. Parasitenkde, xiv, p. 739. Chloromyxum elegans, Braun, 1894, Centralbl. Bakt. u. Parasitenkde, xv, p. 87. Synonymy.—In 1890 Thélohan described the present species and JM. medius as spores occurring in the renal tubules of G@. aculeatus and P. pungitius. He remarked that the 2 entirely different forms of spore are found in close association, occurring not only in the same kidney, but side by side in the same tube of the kidney. Their relation to each other could not be determined, as he was unable to trace them back to the myxosporidium. M. Thélohan writes me (1893) that: In putting an interrogation point in regard to the presence of Spharospora elegans in the kidney of Lota lota, 1 had in mind Balbiani’s fig. 41. The spores which that figure represents are indeed a little less regularly spherical than those of Sphwro- spora and present a more pronouncedly attenuated extremity. Not having observed Myzxosporidia in the Lotas that I have been able to examine, I do not know whether these fish contain exactly the same species as G. aculeatus. The figures of Lieberkiihn (Miiller’s Archiv., 1854, pl. 14, figs. 5,6) certainly do not belong to Spherospora. They, in fact, present 4 polar capsules, and are rather near Chloromyxum jlwiatile. till they form, I believe, a distinct species. A close study of these figures has led me to doubt seriously whether Balbiani’s fig. 41 can be correlated with Chloromyxum (Spherospora) elegans. The whole question hinges upon the number of capsules in Balbiani’s spore. The close similarity between his figure and Lieber- kiihn’s fig. 6, the fact that quadricapsulate forms have frequently been figured by the authors as bicapsulate, and finally the close approximation in habitat (kidney and urinary bladder of same fish’), all point toward the synonymy given above. Oyst none; myxosporidium unknown. Spore.—Round, nearly spherical, untailed, 8 to 10 4 (Thélohan, 1892; 9 to 12 yw, ibid., 1890). Ridge present, terminating ina slight projection at each end of the spore. Habitat.—Almost constantly present in the renal tubules of Gasteros- teus aculeatus (stickleback) and those of Pygosteus pungitius (9-spined stickleback); ? also in kidney of Lotalota® (ling); “ accidentally” pres- ent in kidney of Phoxinus phoxinus L., ovary of G. aculeatus and that of P. pungitius (all fide Thélohan; the last two in a letter to the author, 1893). Hffects.—See p. 248. 1Balbiani does not give the seat. Thélohan cites it as the kidney (fide specimens in Collége de France ?). 2The form habitant here I have referred to Chloromyxum mucronatum (see that species, and the paragraph above in this one). THE MYXOSPORIDIA, OR PSOROSPERMS OF FISHES. 267 89. Chloromyxum (Sphzrospora) ohlmacheri Gurley, 1893. Pl. 40, fig. 8; pl. 41, figs. 1-3. (Myxosporidia of Bufo lentiginosus Shaw, Ohlmacher, 1893, Journ. Amer. Med. Assoc,, XX, pp. 561-7, plate, figs. 1-4.) Chloromyxzum ohimacheri, in Whinery, N. Y. Med. Journ., Lyi, pp. 660-662, figure. Cyst unknown. Myxosporidium.—No myxosporidium could be detected. From this Ohlmacher concludes that: It is probable that, in this case, the parasite did not reach its adult condition in its batrachian host, but here only passed one stage of its existence, that is, the spore Stage. Spore.—Transversely elliptic, about 6 «long and 8 y« broad. Shell bivalve, valvejunction plane perpendicular to the longer axis of the spore; staining with gentian violet (Graim’s method); exhibiting a well-defined undulate-parallel longitudinal striation, the optical expression of the spiral-coil structure of the shell. Ridge present, marking the line of junction of the valves. No loosened band (appar- ently springing, like a loosened barrel hoop, from the uniting edges of the spore-valves), such as Lutz describes, could be demonstrated. Relative to the arrangement of the spore contents, Ohlmacher says: On the side of the pole corpuscles opposite the plasmatic body the vacuole occurred. This space was unstained in specimens in which the excess of stain had been washed out; but in overstained spores the vacuole retained the dye, though not so strongly as the pole corpuscles and the plasmatic body. Interpreted in connection with the orientation of the spore, this may be construed to mean that the contents of the shell cavity consist (from before backward), first, of a clear, nonstaining space (part of the peri- cystic space, and of course not to be confounded with the vacuole, which is intra-sporoplasmic); next, the capsules, and last (and most poste- rior), the sporoplasm.! Capsules: Lying side by side, 2, occasionally only 1, a condition explicable, at least in part, Olilmacher thinks, as spore mutilation in the technique; length, 3 to 3:5 4; staining bright red, but showing no evi- dence of structure with Pfitzner’s alcoholic safranin. Relative to their position, OhImacher remarks that— The situation of these polar corpuscles on the side of the spore is peculiar, and in this respect our myxosporidia differ from those thus far described. As shown below, this view is due to a nonorientation of the spore. In safranin preparations the bright red capsules were frequently observed outside of the spores in the tissue of the kidney. Whether these extra-sporal capsules had migrated during life or had been dis- placed by the technique, it is, Ohlmacher says, impossible to assert positively. He continues: T am of the opinion, however, that the migration of the pole corpuscles is a natural phenomenon in these organisms, and that it has as much or more weight in the life 1 Subsequent examination of the spore confirmed this orientation. 268 REPORT OF THE COMMISSIONER OF FISH AND FISHERIES. history than the migration of the plasmatic mass usually described. The preéseiice of many empty capsules! in the sections would lend weight to this view of the expulsion of the contents of the spore, and in fig. 4a I have represented a. capsule! with a single pole corpuscle, which appeared to be in the act of escaping through a rent in the capsule. Filaments best seen in sections, stained with Babes’s anilin-water safranin where they stain prominently yellow; length varying consid- erably, many occurring curled up at the end as though only partly unwound, measuring when fully projected 6 to 8 times the spore-breadth, extending far into the surrounding tissues; sometimes dimly visible through capsular wall; extruded parallel to the shorter (antero-poste- rior) diameter of the spore. Sporoplasm varying considerably in size and shape, and sometimes filling all the extra-capsular portion of the shell cavity; in this con- dition presenting no evidence of segmentation. In other cases less extensive, being sometimes very small and shrunken,” the sporoplasm then frequently showing a well-defined segmentation, the line of division extending through its middle [i. e., coinciding with the vertical plane]. Each sporoplasm-half envelops, in the form of a well-defined crescent, the corresponding capsule. Nonvacuolate (letter to author, 1893), The sporoplasm stains with Pfitzner’s aleoholic safranin a light pink- ish hue. appearing under a Leitz ;'; in anilin-stained sections, delicately granular; no other structure discernible. Nucleus and evidence of nuclear contents invariably absent. Obimacher adds: I could not even demonstrate the micrococci-like particles in the plasmatic body, as have been described by Lutz, or the satranophile particles of Biitschli. Micro-chemistry: Ohlmacher finds the sporoplasm constantly cyan- ophilous, the capsules constantly erythrophilous. This occurs with carbolic fuchsin and carbolic iodine green (Russells method); the capsules staining a brilliant red, the sporoplasm light green. The tint of the sporoplasm (consequently also the degree of dichromophilism) varies from violet to a well-defined green. This difference depends in large part on the developmental stage of the sporoplasm. Where large and unsegmented and occupying a large part of the shell cavity the green stain was less clearly defined; where more condensed and divided into the 2 crescents closely applied to the capsules, the green was well marked. A striking differentiation is produced by Pfitzner’s alcoholic safranin, followed by aqueous methyl blue, rapid washing in alcohol, and clearing in xylol. The Biondi-Heidenhain triple stain and Wat- asé’s cyanin-chromatrop failed, a result attributed to nonpenetration of the shell by the stain. On the other hand, the success of fuchsin- jodine-green and safranin-methyl-blue seems, Ohlmacher says, to be due solely to their more powerful staining properties, which permit them to penetrate the somewhat resistant shell. This dichromophilism of the capsule and sporoplasm Ohlmacher com- 1 By this term he ineans the spore-shell. 2Due, I think, to absolute alcohol fixation. vad THE MYXOSPORIDIA, OR PSOROSPERMS OF FISHES. 269 pares with the observations of Auerbach and others,! but without affirming Auerbach’s interpretation of dichromophilism as indicative of nuclear bisexuality. Habitat.—Host: Bufo lentiginosus Shaw (a toad). The single speci- men was a large female, sent with a lot of frogs (which latter showed no unusual mortality) from fle country to the laboratory early in September. A gradual increase in size took place in the toad and finally became particularly noticeable, but this was unconsciously ascribed to development of ova. About November 15 the specimen was noticed lying on its back, apparently dead, showing on careful examination, however, a faint flutter of the pleural wall over the heart, but no respiration. Dr. OhImacher has kindly informed me (letter, 1893) that the loeality whence all the specimens were obtained is Sycamore, De Kalb County, Iilinois. Three more specimens of B. lentiginosus collected there July, 1893, showed the same myxosporidian species, but not in such numbers. All of the toads thus far examined have been females. (Later the same condition was found in the males.) Seat: Almost invariably present in larger or smaller groups in the lumen of the urinary tubules; never within the epithelial cells, which latter never show the nuclear metamorphosis occurring with the intra- cellular Sporozoa; occasionally found in sections among the blood cor- puscles in the large blood vessels, it being here impossible to say that it might not have been due to displacement during the technique; never found in the glomeruli; occurring sparingly in the collapsed folds of the urinary bladder, always on the bladder surface, never imbedded in the bladder wall; also free in the urine. Microscopic technique-—Vixation by absolute alcohol or Flemming; imbedding in xylol-parafiin; affixing by the water-albumen method; staining with various anilins. Mode of infection.—As to the origin of the yxosporidian infection, it can only be conjectured, Ohlmacher says, that it must have occurred by way of the cloaca to the bladder, and from here the parasites ascended the urinary passages. It is probable that in this case the parasite did not reach its adult condition in its batrachian host, but here only passed one stage of its development, the spore stage. Pathology—Abdomen containing a large quantity of straw-colored, serous fluid derived from the abdominal cavity and the subeutaneous lymph sinuses; to this fluid the distension was in large part due. The organs showed nothing unusual, except that the urinary bladder was 1 Ohlmacher gives reference as follows: Auerbach, Ueber einen sexuellen Gegen- satz in der chromophile der Keimsubstanzen ; Sitzgsber. k. preuss. Akad. d. Wissensch. Berlin, June 25, 1891, pp. 713-750; Adamkiewicz, Untersuchung ii. d. Krebs u. d. Princip. seiner Behandlung, Wien u. Leipzig, 1893; Noeggerath, Beitriige z. Struktur u. Entwickelung d. Carcinoms, Wiesbaden, 1892; Watasé, Journ. Morphol., 1892. v1, pp. 481-493. 270 REPORT OF THE COMMISSIONER OF FISH AND FISHERIES. largely distended and the kidneys were twice the normal size. Ovaries moderately developed, but not sufficiently to account for the abnormal distension. Besides the Myxosporidia, the kidneys showed an extensive invasion of bacteria. i ffects.—There can, Ohlmacher says, be scarcely any doubt that the Myxosporidia were the direct factors in the pathologic changes. Their number was very great, the tubules of both kidneys being filled. The mere mechanical effect must have been obstruction of secretion and as a remote result ascites and general cedema. Undoubtedly the presence of large numbers of bacteria (to be regarded as a secondary infection) was a potent factor in hastening death. Subsequent comparisons with sections of the kidneys of other toads show the tubules in the first toad to have been dilated and their lining cells to have been flattened and less rich in protoplasmic material than normal. The kidneys of the 5 comparatively slightly infected toads collected in July, 1893, showed no macroscopic lesions. Microscopically no bacteria could be found. The absence of the bacteria, Dr. OhImacher thinks, probably had as much weight in determining the comparative innocuity as the smallness of the number of Myxosporidia (letter, 1893). Through the kindness of Dr. Ohlmacher I have been enabled to examine his specimens, and can add the following: Orientation of the spore—The capsules are 2. in 1 group, anterior; valve-junetion plane, vertical; shorter axis of spore, antero-posterior ; longer axis, transverse. Sporoplasm showing no evidence of a vac- uole, even in iodine-stained sections. Beyond a slight median notch in its posterior border (produced, I believe, by a slight inward, as well as outward, projection of the ridge), Iwas not able to find any evidence of sporoplasm-segmentation, and am therefore compelled to regard this as an optical illusion, produced by the overlying ridge and reinforced by the posterior median notch. This orientation necessitates the reference of this species to Chloro- myxum (Spherospora). From C. (S.) elegans it is distinguished by its transversely elliptic outline and its dimensions. The fact of its iden- tical organal distribution (renal tubules) should also be noted. Finally, Dr. J. B. Whinery has recently published the results of a careful detailed restudy of this species. Ue gives the following tabie, showing the equivalence of Ohlmacher’s nomenclature with that I have adopted: Ohlmacher’s term. Present equivalent. Cansnless-= 2 omen Shell. Pole corpuscle......--| Capsule. Plasmatic mass. .-.--- Sporoplasm, Projectile thread...... Filament. Seley We Saban AbASbeme cas Anterior and posterior ends. TG asd on accoecanSon Sides. Wa CTIOLO lz ccmiaemeee esi Pericystic space. THE MYXOSPORIDIA, OR PSOROSPHRMS OF FISHES. 201 From Dr. Whinery’s paper the following data are condensed: [Page 660] Allthe toads examined (about a dozen in all) were from Sycamore, De Kalb County, 60 miles west of Chicago. The toads were kept in the laboratory sink, and taken from this, from time to time, for examination. The extent of the infection must vary with the surroundings and environment of the animals. Seven toads examined—2 males and 5 females—showed 1 male and 4 females infected. It is quite probable that the mortality was increased by the con- finement in a comparatively small space. During the confinement the toads became stupid, moved about but little, and in 2 or 3 days began to die, 1 dying every day or two. Some of them lived about 3 weeks. Before death no change in external appearance was noticed, except in some cases a distension of the abdomen. Post mortem some increase in amount of peritoneal fluid was usually noticed, but in the toads examined by Whinery this was never so large in amount as in the toad examined by OhImacher. The abdominal viscera showed signs of congestion; the intestines being usually distended with gas and the kidneys enlarged and in a congested state. The parasites were found only in the tubules and in the urinary bladder, and in the spore stage. Ohlmacher’s view that they probably kill by mechanical pressure seems very plausible onaccount of the large number of parasites in the tubules. [Page 661] This number varies in different specimens; sometimes only scattering tubules, in other cases large areas of tubules being filled with parasites. They were never found in the glomeruli or epithelial cells. In the bladder they were found in the folds of the mucous membrane. Ohlmacher has found them in urine collected during chloroform narcosis, in a clean basin. Detailed Morphology of Spore.—Length about 6 4; breadth about 8 jz; size slightly varying in the same preparation. Shape, slightly oval. Shell, showing a distinct striation, the strive appearing to proceed from the shell of each lateral half and to center at the valve-junction, midway between the anterior and posterior ends. Spore showing ut each end a slight projection,! running between which 2 points is the faint transparent ridge, marking the valve-junction. The projections represent the vertical optical section of the ridge. The spore is thus composed of 2 valves, their junction plane dividing the spore into 2 symmetrical halves. Twosmall knob- like thickenings (which show well in the fresh, unstained spore) can be seen at the anterior projection, 1 belonging to each valve. The spores often show cleavage at the anterior end along the line of the valve-junction. Capsules 2, round, 3 / to 3°5 je on an average, situate at the anterior end, 1 in each valve. A filament arises from each capsule, and, penetrating the shell, leaves the spore at the anterior end. The eapsules seem to have the power of projecting and drawing in these filaments. Length of filaments often more than 4 to 8 times the diameter of the spore. Just after entering the spore, before reaching the capsule, they often appear in a spiral roll preparatory to being coiled in the capsule. Sporoplasm situated in the poste- rior end, extending to the sides, in form approaching a crescent; not completely filling the space posterior to the capsules; under high powers (4, Leitz) appearing homogeneous and finely granular; showing in fresh preparations the more highly refractive granules designated nuclei by Thélohan; these apparently vary in number and position in fresh spores, and never appear in hardened and stained preparations.? A vacuole could not be discovered in this species. 1“Termed by Gurley the ‘micronate [mucronate] projection.’” This name was employed by me in a letter in a general sense only (a mucronate projection) and was not intended as an additional special term. ?Ohlmacher had only hardened material, a fact which, Whinery thinks, explains his failure to find nuclei. Ican not believe, from Dr. Whinery’s description, that the bodies he calls ‘‘nuclei” are really such, since they disappear entirely in hardened and stained specimens. AlthoughI have not seen Dr. Whinery’s material, I venture to suggest the possibility of their being fat globules. 972 REPORT OF THE COMMISSIONER OF FISH AND FISHERIES. Micro-chemistry.—The parasites were studied fresh (by teasing kidney tissue, and examining this ina hanging drop, or in fluid media of different kinds), and also after treatment with various fixing and staining agents. In the fresh state, a dilute solution of potassium hydrate caused a swelling of the spore, and brought out the shell and filaments plainly. Glycerin acts well as a medium for the examination of thefresh spore. Probably the best medium to use for the hanging drop is toad’s urine. Iodine (aqueous solution) colors the spore a uniform brown. In fixing cover-glass preparations, no advantage was gained by fixing them in alcohol and ether, or in osmic acid, over that obtained by passing the covers through a flame. In the fresh state the filaments were made plainer in fixed cover-glass preparations [Page 662.] by a number of reagents. Aqueous methyl blue and Babes’ anilin water safranin bring the filaments into view quite satisfactorily. As fixing agents, Flemming’s solution, Heidenhain’s mercuric chloride solution, absolute alcohol, Carnoy’s acetic alcohol, and Perenyi’s fluid were tried, the first and last being found unsuitable on account of the production of shrinkage and distor- tion. The fixed material was imbedded in xylol paraffin by the usual methods. Numerous separate and combined stains were employed with varying results, the cap- sules with almost all stains showing the greatest affinity for the coloring matter, the degree of affinity varying somewhat in different spores. Pfitzner’s safranin is espe- cially good, with a striking affinity for the capsules. Ohlmacher’s dichromophilism was demonstrated with fuchsin and iodine green (Russell’s method), and with safranin and methyl] blue (Ohlmacher’s method). ‘‘This chromophilous reaction is a very striking and possibly significant phenomenon in these organisms.” 90. Chloromyxum (Sphezerospora) perlatum Gurley, 1893. Pl. 40, fig. 2. (Psorosperm of Acerina cernua, Balbiani, 1883, Journ. de Microgr., vu, pp. 201, 204, fig. 44; ib., Balbiani, 1884, Légons sur les Sporozoaires, p. 133, fig. 40.) Myxobolus perlatus, Bull. U. S. Fish Com. for 1891, x1, p. 415; ib., Braun, 1894, Centralbl. f. Bakt. u. Parasitenkde, xv, p. 87, No description (see also p. 265), Habitat.—On Acerina cernua L. 91. Chloromyxum (Spherospora?) sp.incert. Pl. 40, fig. 3. Spore of Lota vulgaris, Biitschli, 1882, Bronn’s Thier-Reich., 1, pl. 38, fig. 22. Cyst unknown. Myzxosporidium.—Not described. The sporoblast produces a single spore?! Spore.—Not described. For the reasons given on p. 265, the present generic reference of this species is probably the correct one, and the species should be closely compared with C. mucronatwm. Habitat.—Ovary of Lota lota L. (= vulgaris); ling. 1“ Hach spore in a special transparent membrane,” oY, ad | THE MYXOSPORIDIA, OR PSOROSPERMS OF FISHES. 273 92. Chloromyxum (Sphzrospora) dujardini Thélohan, 1892. Pl. 40, figs. 4-7. Cyprinus Cyprinus| eryth- rutilus, | roph- “psoro- |thalmus, dujardini. Date. Authority; reference. sperms’’ | ‘‘psoro- of. sperms” of. x Mites eaccaa- soe sees 1841 | Miiller, Miiller’s Arch., pp. 481, 486, pl. 16, fig. 4b, c. x Debye esos boeeeeets 1843 Miiiler, | Rayer’s Archiv. Méd. Comp., I, p. 226, pl. 9, fig. 40, ¢. we) WAS So Ree Re aeeeiasorsac 1843 Rayer, Rayer’s Archiv. Méd. Comp., I, p. (pars.) 269. BE oe Sere arse 1845 | Dujardin, Hist. Nat. des Helminthes, p. 644, pl. 12, fig. 12 N,, 12 No, x SES) [a aoe aie te 1853 | Robin, Hist. Nat. Végét. Par., p. 299, pl. 14, (pars.) a eations 6. gma ara on raw ell aia’ ayciniciajalare mimo e 1882 Biitsehli, Bronn’s Thier-Reich., I, pl. 38, fig. 5. Myxosoma et} 1892 Thélohan, Bull. Soe. philom: it. Paris, IV, p. Mixosoma .-.! 175. Chloromyxum| 1893 | Gurley, Bull. U. 8. Fish. Com., XI, p. 419. Myxosoma ..-| 1893 | Braun, Centralbl. Bakt. u. Parasiteukde, | esse too: adonconeé=|SOeseo sec Chloromyxum | 1894 | Braun, Centralbl. Bakt. u. Parasitenkde, | | | XV, p. 87 Synonymy.—The first 6 references in the table, except those to Dujar- din and to Biitschli, represent the same form, the later being mere copies of Miiller. The fusion of the form observed by Dujardin with that ob- served by Miiller is on the authority of Théelohan, who states (letter to the author, 1893) that he has observed his Myxosoma dujardini upon both Leuciscus rutilus and L. erythrophthalmus, and that he believes that Miiller’s and Dujardin’s figures represent the same species. Biitschli’s form is also probably referable here; size of the last, 0-46 mm. Concerning the form observed by hints in Leuciscus r til us, Miiller says: Once there was found on the pseuclobranchias ( Nebenkiemen) a mass of small yellow cysts. The size of this mass was 4 lines. This time all the cysts contained elongate capsules [spores] with pointed anterior and bluntly rounded posterior ends (fig. 40). On the flat border the convex surfaces were exactly equal and the 2 diverging vesi- cles were attached interiorly at their points. Thus this form was never found coexisting in the same cyst with Myzxobolus cycloides. Considering the great frequency of occurrence of the latter species such coexistence would be expected if they were merely different forms of one species. Their persistent nonassociation thus strongly reinforces the argument in favor of their specific distinct- ness drawn from their different characters. Cyst not described. Myxosporidium.—Spores imneddeds in and held together by an almost diaphanous, ramified, glutinous mass, 1°25 to J:50 mm. long, decompos- able by water, analogous to the amcebe, apparently destitute of an envelope (Dujardin). Spore.—Oval, pointed anteriorly, broadly rounded posteriorly, length, 10 to 12 yu (0-0051’’’ to 0:0054/’’); breadth, 7 yz (0:0034/’’) untailed; cap- sules 2, of equal size (Miiller). Habitat.—Encysted in the pseudobranchize of Leuciscus rutilus from German rivers; branchial lamelle of Leuciscus (Scardinius) erythroph thalmus from the Vilaine, at Rennes, France, F c——18§ | 274 REPORT OF THE COMMISSIONER OF FISH AND FISHERIES, V. CERATOMYXA Thélohan, 1892. Etymology not given. ' Bull. Soc. philomat. Paris, 1v, pp. 169, 171, 175; ib., Gurley, 1893, Bull. U.S. Fish Com. for 1891, x1, pp. 411-12, 420; ib., Braun, 1893, Centralbl. f. Bakt. u. Parasitenkde, xIv, pp.738-9; ib., Braun, 1894, Centralbl. f. Bakt. u. Parasitenkde, xv, p. 87. ; Definition.—Chloromyxide with bilaterally symmetrical, transversely extended, subisosceles-triangular spores whose breadth greatly exceeds the length; valves hollow-conical with solid tips; sporoplasm unilater- ally and asymmetrically situated; typ, C. spherulosa. The position of this genus in the system depends upon the interpre- tation of its symmetry. Admitting (as we may safely do) that the position of the capsules marks the anterior extremity, the question arises whether the plane of junction of the valves is the vertical or the longitudinal. If it be vertical, we then have: (1) Vertical plane inter- capsular; (2) spore latérally extended; (3) valves bilaterally subsym- metrical; (4) decided sporoplasmic bilateral asymmetry. On the other hand the supposition that this plane corresponds to the longitudinal necessitates the following suppositions: (1) That the ver- tical plane can be percapsular; (2) that the spore is vertically extended; (3) valves superior and inferiorly subsymmetrical; (4) decided (sporo- plasmic) supero-inferior asymmetry. While admitting the striking anomaly exhibited by this species in its bilaterally asymmetric distribution of the sporoplasm (which cer- tainly warrants its generic separation), it seems more easy to accept this than to admit (a) that the longitudinal plane can be percapsular, ' and (b) that the spore is greatly extended supero-inferiorly, of neither of | which conditions any other known species exhibits an example. There are, however, species which exhibit, though in a less degree, bilateral asymmetry (Myxobolus unicapsulatus, M. inequalis, M. strongylurus). Two other characters should be noted. As in the other forms hab- itant in the fluid-filled organs, the Ceratomyxa species are never seen “encysted.” Further, 3 out of the 4 known species possess the strik- ing peculiarity of bisporogenesis, each myxosporidium producing only 2 spores. The fourth species presumably (from Thélohan’s silence) does not possess this character. It is well to note that this character is possessed by only one other species, viz: Perugia’s Myxosporidium mer- lucit, a gall-bladder species provisionally and doubtfully referred to Myzxobolus (see p. 242). Finally, while this paper was passing through the press, M. Thélohan’s recent paper”? was seen. It seems to imply very strongly two things, ‘No known instance exists of 2 capsules being placed one above the other (i. e., in the vertical plane, which would thus be percapsular). The only species in which by any possibility the vertical plane could be asserted to be percapsular is Cysto- discus? diploxys, but here the condition is at least equally we'l (and I think much better) explained on the view that the intercapsular plane is the vertical. 2Compt. Rend. Acad. Sci. Paris, 1894, cx vu, pp. 428-430. THE MYXOSPORIDIA, OR PSOROSPERMS OF FISHES. 219 viz: (1) That bisporogenesis must be admitted as a (very striking) generic feature; and (2) thatif, as Perugfa asserts, Myxobolus merlucii possesses this character, it isin all probability a Ceratomyxa, and not a Myxobolus. And two facts confirm this latter view, viz: The improbability in Myxo- bolus of a gall-bladder habitat and the rarity of spores whose breadth exceeds the length. Perugia’s species is, however, provisionally left under Myxobolus, on account of his positive statement as to the presence of an iodinophile vacuole. The following is an abstract of Thélohan’s paper: Besides the species formerly published! in which the myxosporidium produces but 2 spores, I have since confirmed the same peculiarity in a rather large number of new forms in the gall-bladders of certain Mediterranean fishes, All these 2-sporing species belong to:my family ‘‘ Myxidiées,” the greater part of them being clearly referable to Ceratomyxa, while the others, by successive modifications of spore-form, establish a transition between that genus and Spherospora. This last connects the 2-sporing species with the many-sporing, and at the same time, by its habitat, the free species to the tissue-imbedded forms. There is thus no absolute separation between the 2-sporing and the other Myxospo- ridia. The 2-sporing always live a free amceboid life in the bile-fluid and exhibit a very great motility, owing to specialized pseudopodia heretofore described. These 2-sporing Myxosporidia with localized pseudopodia and rapid movements represent the most elevated type of organization. As regards the interpretation of the facts, are they perfected types derived from inferior, or are they gee 230) the primitive type, the others, especially the tissue-imbedded species, being forms degraded by a more pronounced (a, so to speak, more intimate) parasit- ism? Thélohan favors the latter view. Great stress is to be laid upon the pro- gressive increase in the number of spores occurring pari passu with degradation of form and increase of parasitism, such increase of reproductive elements being always one of the most constant attributes of parasitism. [Page 429] [P 84. Ceratomyxa arcuata Thélohan, 1892. Compt. Rend. Acad. Sci. Paris, cxv, p. 1091. Cyst none. Myxosporidium.—Of variable form, diameter apparently not exceed- ing 35 or 40 yw; destitute of prolongations. Endoplasm finely granular and homogeneous, containing some scattered fatty globules; destitute of spherules. Pseudopodia ectoplasmic, lobed; the filiform variety absent. Spore.—Relatively very small; length, 5 4; breadth, 40 Habitat.—Gall-bladder of Onus tricirratus (=Motella tricirrata) col- lected at Roscoff, in August, 1892. Remarks.—This differs from the other species of the genus princi- pally in its much smaller size. 85. Ceratomyxa agilis Thélohan, 1892. Compt. Rend. Acad. Sci. Paris, cxv, pp. 962-3. Myxosporidium.—Attaining a maximum length of 85 yu, and a maxi- mum breadth of 20 4; asswning various forms, most frequently elong- ated, subcylindric, a little swollen at the middle. One end (which on account of being constantly foremost in progression is to be regarded 1Compt. Rend. Acad. Sci. Paris, 1894, cx vi, pp. 428-430. 276 REPORT OF THE COMMISSIONER OF FISH AND FISHERIES. as the anterior), rounded; the other (posterior) usually attenuated, pointed, sometimes, however, swollen, rounded or bifurcate, or 7-, or 8- (or more) lobed. Limit between ectoplasm and endoplasm almost indistinguishable; myxoplasm finely granular, presenting constantly, near the anterior end, grouped in variable number, some small, very refringent, fatty globules. Pseudopodia differing markedly from those of other Myxosporidia, always limited to anterior end; number variable up to 7 or 8, perfectly distinet from one another, almost filiform, progressively attenuating to their drawn-out pointed extremities; length very considerable, ad maw. one half that of the myxosporidium; composed of exceedingly fine granular plasma resembling the ectoplasm of other Myxosporidia, whence their ectoplasmic nature may be inferred. Movements of pseudopodia very rapid, describing a semicircle, always from before backward. Thélohan could not determine whether, upon arriving at their limit of backward motion, the pseudopodia fuse with the myxosporidium or move forward to repeat their sweep. Loco- motion of myxosporidium thus produced, relatively rapid (3 times its length in 25 seconds). Remainder of myxosporidium motionless, appar- ently, however, possessing a certain contractility, as is seen when the anterior (pseudopodial) end becomes lodged against an obstacle. Spore.—Similar to that of Ceratomyxa spherulosa; breadth 60 yu. Never more than 2 spores in one myxosporidium. Habitat.—Free in the gall-bladder of Dasyatis pastinica L. (= Trygon vulgaris) sting-ray at Concarneau in September, 1892, 86. Ceratomyxa appendiculata Thélohan, 1892. Compt. Rend. Acad. Sci. Paris, cxv, pp. 963-964, Cyst none. Myzxosporidiwm.—Presenting special characters which clearly dis- tinguish this species. Fully developed forms assume very irregular and very variable shapes; remarkable for the presence of 1 to 4 or 5 immoy- able prolongations, composed of an endoplasmic axis and an ectoplasmic covering, which extend out from a central portion of a very variable form. Length of prolongations may reach twice the diameter of the central portion. Pseudopodia lobed, originating from the ectoplasm of the central mass at no fixed point, which is changeable from moment to moment. Spore-formation.—Taking place in the above-mentionea central por- tion, each myxosporidium producing 2 spores. Spore.—Length (?), 5 to 8 uw; breadth (7), 65 yu. Habitat.—Free in the gall-bladder of Lophius piscatorius (angler) collected at Roscoff and at Le Croisic in August and September, 1892, THE MYXOSPORIDIA, OR PSOROSPERMS OF FISHES. 277 87. Ceratomyxa sphzrulosa Thélohan, 1892. Pl. 41, fig. 4. Bull. Soc. philomat. Paris, Iv, pp. 171-3, 175, fig. 1; ib. Thélohan, 1892, Compt. Rend. Acad. Sci. Paris, cxv, pp. 961-2; ib. Gurley, 1893, Bull. U. S. Fish Com. for 1891, x1, p. 420; ib. Braun, 1893, Centralbl. f. Bakt. u. Parasitenkde, xiv, pp. 738-9; ib. Braun, 1894, Centralbl. f. Bakt. u. Parasitenkde, xv, p. 87. Cyst, none. Myxosporidium.—Spheriecal or ovoid; youngest stages exhibiting very distinct amceboid movements, colorless; older individuals yellowish, presenting a very remarkable constitution. Ectoplasm thin, emitting lobed pseudopodia, with very slow movements. Endoplasm appearing riddted with small (3 or 4 yz) clear spheres between which lies a gray- ish, finely granular plasma. Spheres often exhibiting, grouped at their center, a variable number (most frequently 5 or 6) of small yellow, brown, or greenish granules which resist nitric acid and potassium hydrate longer than the spheres which envelop them. Thélohan was unable to express any opinion as to the nature of the spheres, which, he remarks, constitute one of the most remarkable peculiarities of this species. Spore formation.—Each myxosporidium forms at the most 2 spores; never more. Solid distal portion of valve folded back along the pos- terior border during development. Thélohan notes the similarity in this respect to the development in the tailed Myxrobolus species (see p. 248) and says that the anterior convexity of the curve presented by the long (transverse) axis seems the effect of this primitive arrangement. Spore.—Transversely extended, symmetrically (or subsymmetrically) double scalene-triangular; length, 8 to 10 or 12 4; breadth, 90 to 100 yw. Shell bivalve; valves right and left; symmetrical or subsymmetrical ; shape of each valve hollow-conical, with the distal extremity solid for a variable distance; valves united along the cone bases, a slender ridge marking their line of junction. The shell cavity thus consisting of 2 (lateral) halves, one of which is always occupied by a variable number of small very pale masses whose exact nature is unknown, but which seem to represent the residue of capsule formation. Sporoplasm.—Constantly situated in the other half.of the shell cav- ity, of which it occupies only a relatively very small portion; finely granular; no iodinophile vacuole. Capsules.—T wo, the largest known, filament very clearly seen, coiled; extrusion easily produced by potassium hydrate or ether, each capsule presenting as a rule a special opening placed on one side of the suture. Habitat.—Gall bladder (free floating in bile) of Galeus mustelus (=Mustelus vulgaris) smooth dogfish and of Galeorhinus galeus (= Galeus canis) taken at Valéry-au-Caux, by Balbiani, in August, 1891. 1Thélohan gives the dimensions reversed (7. e,, a8 length 100, breadth 8 to 10 or 12 ~) but this is of course a wrong orientation. Similarly with other species. 973 REPORT OF THE COMMISSIONER OF FISH AND FISHERIES. Fam. CYSTODISCIDZ Gurley, 1893. Bull. U. S. Fish Com. for 1891, x1, pp. 412-13; ib., Braun, 1894, Centralbl. f. Bakt. u. Parasitenkde, Xv, p. 87. Definition —Phenocystes whose spores possess antero-posterior and bilateral symmetry; capsules in 2 groups situated at the (anterior and posterior) ends; a bivalve shell, the plane of junction of whose valves is perpendicular to the longitudinal plane; condition of sporoplasm unknown; type genus Cystodiscus. To the family as thus defined, I have provisionally (by way of taxo- nomic necessity) approximated Thélohan’s genus Spheromyxa. It is characterized, Thélohan says, by the structure of the spores, especially by the form of the filaments and their disposition in the capsule. In the absence of figures, the orientation of the spore, upon which classi- fication must be based, is uncertain. The double grouping of the cap- sules necessitates the approximation (at least among known genera) of this genus to Myxidiwm or to Cystodiscus. Between the last two, the presence of a membrane around the myxosporidium and especially the bivalve structure of the spore would seem (at a taxonomic guess) rather to approximate Spheromyxa to Cystodiscus. It may be frankly admitted that, as at present composed, this family is somewhat unsatisfactory and must be held subject to revision, prob- ably in the direction of elision. For of the species with the capsules in 2 groups we now know (excluding Mywxidium ? sp.102, about whichhardly any data exist) 5 species: Cystodiscus immersus, Cystodiscus ?? diploxys, Spheromyxa balbianii, Myxidium lieberkiihnii, Myxidiwum ? ineurvatum. Of these M. lieberkiihnit presents a sufficiently distinct group of char- acters to warrantits delimitation as the type of a family. The other 4 species then agree in two very important characters, viz: 1. Arrangement of capsules in 2 groups. 2. Presence of a bivalve shell. Further than this, however, our analysis can not, for want of data, be at present safely pushed. Indeed, I have even left Mywxidium ? incurvatum under Myxidium (where in all probability it does not belong) rather than place it elsewhere at random. Obviously the next step is the determination of the 3 symmetry planes and the orientation of the valve-junction plane. I suspect the future will separate generic- ally C. ?? diploxys from C. immersus, the former appearing to have the valve-junection plane parallel and the latter to have it perpendicular to the longitudinal plane. In the present uncertainty, however, espe- cially as long as the symmetry-relations of Sphwromyxa are so dubious, the present provisional arrangement is probably preferable to another new genus, and perhaps a family. ‘ N : THE MYXOSPORIDIA, OR PSOROSPERMS OF FISHES. 279 VII. CYSTODISCUS Lutz, 1889. Etymology not given. Centralbl. f. Bakt. u. Parasitenkde, v, p. 88; ib., Gurley, 1893, Bull. U.S. Fish Com. for 1891, x1, pp. 411-13; ib., Braun, 1894, Centralbl. f. Bakt. u. Parasi- tenkde, Xv, p. 87. Definition.—Characters those of the family; type, C. immersus. Whatever may be the ultimate taxonomic destination of the species here included, the genus will, I think, stand, as it is the first in order of priority, having the spore with the capsules in 2 groups, and a bivalve shell. 97. Cystodiscus immersus Lutz, 1889. Pl. 42, figs. 1-10. Centralbl. f. Bakt. u. Parasitenkde, v, pp. 84-88, figs. 1-10 separately and subsequently; ib., Gurley, 1893, Bull. U. 8S. Fish Com. for 1891, x1, p. 413; ib., Braun, 1894, Centralbl. f. Bakt. u. Parasitenkde, xv, p. 87. Cyst none. Myxosporidium.—Youngest forms unknown. Hoping to find them in the tadpoles, Lutz examined about a dozen, but the gall-bladders were entirely free; in frogs and toads only a little larger, however, myxosporidia were found, but they (even the very small ones, less than 0-1 mm. in diameter) already showed the stiff disk form. In number, usually several, often very many (30 to 50), visible through the bladder wall, appearing macroscopically as round transparent disks or leaflets, as thin as paper, with frequently a whitish border in which the upper and under surfaces meet directly (without the intervention of a lateral surface as in a cylinder); upper and under surfaces very slightly convex, the thickness being only 35 to +4; of the diameter; body-form thus feebly biconvex lenticular, ranging in diameter from the limits of visibility to 1:5 or 2 mm. Ectoplasm forming a plainly perceptible, transparent, structureless membrane, completely resistant to the bile and noticeably so to chemi- cal reagents, disintegrating on prolonged immersion in water; preserv- ing the form of the organism which otherwise almost certainly would, on account of its great thinness, become wrinkled and folded, but whose borders have a subcircular outline. Ectoplasm often containing great numbers of micrococcus-like bodies, which, as they brown only very slightly with osmic acid, can scarcely be pure fat. They also can not be cell-nuclei. Endoplasm containing numerous large vesicles, poly gonal-flattened by mutual pressure, producing the appearance of a cellular structure. Vesicles possessing a subglobular contour, showing no trace of a nucleus; upon rupture of the ectoplasm, escaping spontaneously into the bile, in which (also in alkaline solutions) they immediately vanish under the eyes of the observer, probably on account of the solution of a delicate surrounding membrane and the subsequent solution of their contents. Amceboid movements are completely excluded by the mem- 980 REPORT OF THE COMMISSIONER OF FISH AND FISHERIES. branous character of the ectoplasm. No traces of change of form or place were seen. Spore formation.—Beginning with individuals scarcely one-tenth the maximum size, the number of spores being then, however, relatively as well as absolutely less; number increasing pari passu with growth, individuals of equal size not necessarily showing, however, equal num- bers. In specimens largest and most rich in spores the latter show themselves scattered over the surface at very short intervals, while on the borders they form a compact zone visible macroscopically as a white ring. Pansporoblast?: Myxosporidia of various ages tolerably frequently show a spore-foundation [Sporenanlage] in the form of a smaller, more elongate, and only delicately outlined oval, containing two small pale perfectly round capsules (somewhat removed from the poles), which inclose a tolerably large dark biconcave-ended cylindrical rest-body (Restkorper). The delicately cutlined oval contracts its bulk, its out- line clears up, and the shell and capsules become thicker and very promi- nent. Valve-connection takes place through a process of the shell, and the spore becomes more ventricose. Spore.—Lying outside the vesicles, always arranged in pairs, the lat- ter rather irregularly scattered under and only loosely connected with the ectoplasm, concentrated in greatest numbers along the borders, forming a white ring. Length of mature spore, 12 to 14 uv; breadth, 9 to 10 4; regularly oval, with blunt ends; spore showing no independ- ent movements except filament extrusion. Shell rather thick and firm, indistinctly and finely transversely striate, possessing the usual resistance to chemical reagents; bivalve, the valve- junction plane oblique (like the diagonal of a rectangle), inclined about 45° to the ‘‘equatorial” [transverse?| plane. . This condition doubtless stands, Lutz says, in connection with the position of the capsules at either end, one valve lodging each. Around the border of each valve . is placed, hoop-like, a little elastic rod, plainly projecting in profile, rebounding, when treated with potassium hydrate, in the form of a more or less extended band, the valves thereby becoming loosened, a piece often being torn away. Lutz remarks that these observations agree with Balbiani’s (p. 223). Lutz, however, never saw any connection of spore-pairs through the medium of the loosened bands. Capsules 2, separated, 1 at each end, subglobular-pyriform, slightly sharper anteriorly, glittering strongly in water or in bile, only slightly so in glycerin and other refractile fluids; size diminished by extrusion of filaments, walls plainly double-contoured. Filaments difficultly per- ceivable when fully coiled, plainly visible when half uncoiled; extrusion frequent in bile, not so common in water; extrusion also producible by various reagents, most certainly by potassium hydrate. Length, 4 to 5 times that of the spore-length. Sporoplasm transparent, first becoming plainly visible after the action ‘ fHE MYXOSPORIDIA, OR PSOROSPERMS OF FISHES. 281 of coagulants, as an irregular, very low and _ biconcave-excavated cylinder. Lutz could find no true nuclei, either before or after develop- ment. Micrococcus-like corpuscles (similar to those in the ectoplasm, see above) were present, but on account of their inconstancy, these must be regarded as plasmatic secretions. Exit of sporoplasm.—Never observed, prolonged immersion in water producing only a gaping of the valves, with or without a falling out of the capsules. Habitat, ete.—Gall-bladder (free-floating in and escaping with the bile) of Bufo agua (toad) in every one of 50 half grown to grown individuals taken at the most various times at one locality in Brazil; parasites mostly multiple, sometimes as many as 50; also in young specimens of Cystignathus ocellatus (toad) from 2 localities in Brazil. On the contrary they were absent from 2 large individuals of Bufo agua from other provinces of Brazil. They were also absent from all the tadpoles examined and from metamorphosed toads from several localities. EH ffects—The myxosporidia observed appeared in nowise to impair the histological integrity of the gall-bladder. 98. Cystodiscus ? ? diploxys Gurley, 1893. Pl. 42, figs. 11-13. Pyralis (or Tortrix) viridana, diploxys. Date. Authority ; reference. psorosperms of. ee Ten Dee Sade enaene 1866 | Balbiani, Jonrn. Anat. et Physiol., Paris, IIT, pp. 600-2. ty = = al SRS Se erg ee 1867 | Balbiani, Journ. Anat. et Physiol., Paris, 1V,pp. 275, 276, 335 (footnote), pl. 12, figs. 10-12. . SE Red le Se a Aa ee 1882 | Biitschli, Bronn’s 'Thier-Reich, I, p. 590. 3S NeseR ace Sanbeae 1890 | Pteitter, Virchow’s Arch. f. path. Anat. u. Physiol., CXXII, p. 559. Xie Me aoa ee cae asic 1890 | Thélohan, Annal. d. Microgr., Paris, I, p. 193. OAS ENE aeeee 25s. stk 1892 | Henneguy and Thélohan, Compt. Rend. hebdom. Soc. Biol. Paris, LV, p. 587. hue EAR CB Ss eseseen 1893 | Perrier, Traité de Zool., p. 459. HensaqKeoseee. Cystodiscus?|} 1893 | Gurley, Bull. U.S. Fish Com. for 1891, XI, pp. 411-13. See Sia eee ase 1893 | Braun, Centralbl. f. Bakt. u. Parasitenkde, XIV, p. 739. Ba see eae cs ate Cystodiscus?|} 1894 | Braun, Centralbl.f. Bakt. u. Parasitenkde, XV, p. 87. Cyst.—Spherical, 12 to 15 (in 1 individual 4) in number, 230 to 400 «. Membrane rather thick. Contents rounded masses composed of fine brownish granulations suspended ina viscid homogeneous liquid. In1 cyst (pl. 42, fig. 12) the parasites were mixed with numerous fat-like globules, insoluble in caustic soda; coloring wine red with iodine. Spore.—Greatly resembling the “psorosperms” of fishes; elliptic or slightly flattened, traversed by a ridge apparently marking the line of valve junction. Sometimes showing 2 small brilliant twin grains placed at one of their extremities, sometimes 4 grains disposed in pairs at the 2 “sends”; not visibly affected by concentrated alkalies or feeble acids; becoming brilliant and homogeneous in salt water. Habitat.—In the free state or inclosed in great spherical cysts in the abdominal cavity of the butterfly of Tortrix viridana (an insect). 282 REPORT OF THE COMMISSIONER OF FISH AND FISHERIES. Concerning this species Biitschli says: Balbiani has observed cysts in the body cavity of a butterfly (Pyralis viridiana) which were filled with corpuscles possessing a structure similar to that of the myx- osporidian spore. The observation is, however, not sufficient to demonstrate that it belongs to the Myxosporidia. Thélohan and Henneguy regard it as a myxosporidian, and itis diffi- cult for me to think otherwise. VIII. SPHAZXROMYXA Thélohan, 1892. Etymology not given. Compt. Rend. Acad. Sci. Paris, cxv, p. 1093; ib., Brann, 1893, Centralbl. f. Bakt. u. Parasitenkde, Xv, p. 737. Definition.—Characters to be inferred from those of the type species, S. balbianti. After several vain attempts to draw up a satisfactory generic defini- tion as between this genus and Cystodiscus, | have concluded that at present there are not in the record sufficient data for their accurate delimitation. 99. Spheromyxa balbianii Thélohan, 1892. Compt. Rend. Acad. Sci. Paris, Cxv, pp. 1091-3; ib., Braun, 1893, Centralbl. f. Bakt.u. Parasitenkde, xv, p. 738. Myxosporidium.—Generally visible to the naked eye as a small opaque, more or less regular, usually subspherical mass, occupying a variable part of the bladder and escaping with the bile; yellowish or greenish-yellow, of a relatively firm consistence, permitting of handling. Attempts at teasing render evident the presence of a thin membrane. Under the microscope the myxosporidium shows absolutely exceptional characters. Ectoplasm forming a clear, homogeneous zone, presenting in sections a very clear striation. Hndoplasm more granular, inclosing numerous spores. Spore.—Resembling that of Myxidiwm lieberkiihnii, elongate, slightly swollen at middle; extremities abruptly truncate, cut squarely off, so to speak, so as to present very sharp “lateral” angles; “length” [?] 138 to 16 uw; “breadth” [?] 5 uw. Shell bivalve, finely striate, parallel to the longer axis. Capsules 2, one at each “extremity,” their axes oblique and oppositely directed with reference to the longer [transverse ?] diam. eter of the spore. Filament very peculiar, forming a relatively very short (average length 15 x) cone, the diameter of whose base nearly equals the breadth of the extremity of the spore. Exit produced by iodine water, potassium hydrate, sulphuric acid, etc. The mode of coil- ing is equally peculiar, the axis of the coil being perpendicular to the long axis of the capsule. Sporoplasm forming a single mass, destitute of an iodinophile vacuole; nuclei, 2; the pericornual nuclei (Thélohan’s “nuclei of the capsulogenous cellule”) are also present. Habitat.—Free in the gall bladder of Onus tricirratus and O. macu- latus (= Motella trictrrata and M. maculata); very common, especially at Roscoff. Ee ee t THE MYXOSPORiDIA, OR PSOROSPERMS OF FISHES. 283 Fam. MYXIDIID& Gurley; 1893. (‘‘Myxidiées” (pars) Thélohan, 1892, Bull. Soc. philomat. Paris, tv, pp. 173, 175) ; Myzxidiide, Bull. U.S. Fish Com. for 1891, x1, pp. 412,420; Myxidiea [Thél. ] Braun, 1893, Centralbl. f. Bakt. u. Parasitenkde, xiv, p. 739; Myxidiide, Braun, 1894, Centralbl. f. Bakt. u. Parasitenkde, xv, p. 87. Definition (provisional as regards negative characters).—Phenocystes destitute of antero-posterior, but possessing bilateral symmetry; cap- Sules in 2 groups in the (right and left) wings; no bivalve shell; no vacuole; type (and only) genus Myaidiwm. IX. MYXIDIUM Biitschli, 1882. Etymology not given. Bronn’s Thier-Reich, I, pl. 38; 7b., Lankester, 1885, Encycl. Britan., 9 ed., xIx, p. 855; ib., Thélohan, 1892, Bull. Soc. philomat. Paris, 1v, p. 175; ib., Weltner, 1892, Sitzgsber. Ges. Naturf. Freunde Berlin, p. 351; ib., Perrier, 1893, Traité de Zool., p. 460. Definition—Characters those of the family; type, MW. licberkiihnit. 100. Myxidium lieberktihnii Biitschli, 1882. Esox lucius . ; ; lieber- On, : itv: referenc ‘ psoro- | ahnii. esocis. | Date Authority; reference. sperms ete., of. | — —|—_—— TY eater ares so owne 22 See 1854 | Lieberkiilhn, Miiller’s Archiv., pp. 5,6, 349-52, pl. 14. figs. 1-4. Se 2 Se are iee | Rea Sn ee So 1854 | Lieberkiin, Bull. Acad. Roy. Belg., XXI, pt. 2, Pp. 23. IR Ss tee a eee ala i nma 1879 | Leuckart, Parasiten des Menschen, p. 246, fig. 98. SQM leona cee eecea sway sas 1880 | Gabriel, Jahres-Ber. schles. Gesellsch. f. vaterl. Cultur f.d. J. 1879, LVI, pp. 188-95. ORME MARE eta rctectaltte |Dawe cintste aiars'e 1881 | Bitschli, Ztschr. f. wiss. Zool., XXXV, pp. 638-48, pl. 31, figs. 25-40. ial al | Oo RS Aen Sa 182 | Zoolog. Record for 1881, XVIII, Prot., pp. 34-35. {Wi hi-odhhinenl| 25 sAeoesenae 1882 | Biitschli, Bronn’s Thier-Reich, I, pp. 593-5, pl. 38, figs. 12-15. Reesaaseriealseesceaecees 1883 | Balbiani, Journ. de Microgr., VII, pp. 200-1, 274-5, fig. 64. a alee wfsimiacai| ASE -afeteis = )515 1884 | Balbiani, Lécons sur les Sporozoaires, pp. 126, 129-30, fig. 45. Miyssidinms|e- Se -eit= <2. 1885 | Lankester, Encyelop. Britan.,9 ed., XIX, p. 855, fig. xvii, 34. SOG Fale Sates ok. BSS Sere Rees ee 1886 | Leuckart, Parasites of Man, 2ed., p. 196, fig. 98. Psorosper-| 1837 | Koch, Encyklop. d. gesammt. Thierheilkde u. mium. Thierzucht, LV, p. 94, tig. 668, 1. SO” Wee esas Se Bee nae es aS 1888 | Pfeitfer, Zeitschr. f. Hygien. Leipzig, IV, p. 409. => SSS acoes ib Seer peepee 1890 | Thélohan, Annal. de Microgr. II, p. 198. Semen te sors ek ee ea i890 | Pfeitter, Archiv. f. pathol. Anat. u. Physiol., CXXIT, pp. 559-60. SE Sula a ee | ee 1890 | Pfeiffer, Die Protozoen als Krankheitserreger, 1 ed., pp. 41-9, 55, 98, figs. 12, 18, 15, table, figs. SEE SMD tone ss PER. Fo be 25) Fe 1891 Pfeiffer, Die Protozoen als Krankheitserreger, 2 ed., pp. 20, 91, 105, 127-33, figs. 52, 53, 55. MGye-aid thins eeeoeeneaee 1892 | Thélohan, Bull. Soc. philomat. Paris, IV, pp. 166, 169, 175. MoWpaolhiena|OS seeencesee 1892 | Engler & Prantl, Die natiirlich. Panzenfamilien, Leipzig, Lfrg. 76, fig. 22. epee be smietars eye As acer ecie te 1893 | Perrier, Traité de Zool., pp. 459-60. x* epee Cees ReSmscaeernse 1893 Ohlmachex, Journ. Amer. Med. Assoc., XX, p. 562. Niro lias. Seesecasa = 1893 | Gurley, Bull. U.S. Fish Com. for 1891, XI, pp. 410, 420. IM bes aK bE ate ociso Se 1893 | Braun, Centrabl. f. Bakt, u. Parasitenkde, XIV, pp. 738-9. MEyexieiuims| ese ere ante 1894 | Braun, Centralbl. f. Bakt. u. Parasitenkde, XV, p. 87. Pls. 43-46; pl. 47, figs. 1-5. * Of air bladder; error. 284 REPORT OF THE COMMISSIONER OF FISH AND FISHERIES. The description is based upon the (in the main) accordant results of Lieberkiihn, Balbiani, Biitschli, and Pfeiffer, particularly upon those of the last two observers. Gabriel’s accordant results have been incor- porated, his divergent ones mostly footnoted. Life-history (Pteiffer).—Emerging from the spore, the young myxo- sporidium (until now the sporoplasm) next penetrates into the interior of the red blood corpuscles or of the cells of the bladder epithelium. Its intracellular existence continues until its increasing size ruptures the cell wall, when it escapes, differentiates its own protective ecto- plasmic layer, and resumes amceboid movements. Finally endogenous (pansporoblastic) spore formation takes place, the spores ultimately become free, and the life-cycle is complete. Cyst none. Myxosporidium..—Form varying much with age; at exit from spore globular-amceboid: while within, and at the time of exit from the epithelial and red blood cells, roundish; older forms cylindrical, ribbon or club shaped, or irregularly amoeboid, presenting a very grotesque appearance, with branches, forkings, and long appendages. Size vary- ing with age up to a maximum length of 300 « (Biitschli) by a breadth of 136 4. Youngest myxosporidia colorless; older ones colored yellow- ish or reddish or brownish-red by inclusions of extraneous pigment in the endoplasm. Myxoplasm, in all but the youngest stages, presenting a clear differentiation of ectoplasm and endoplasm. Ectoplasm forming a rather thick, very transparent, colorless, deli- cate, finely granular layer, containing none of the characteristic endo- plasmic elements; end in contact with the mucous membrane, colorless, destitute of granules, leafy or pronged for attachment. Opposite end richest in granules and in pigment, free-floating, usually rounded; free- floating forms partly agreeing with the above, differing, however, in being destitute of pronged processes, showing at times some peculiar differentiations, particularly the appearance shown on pl. 44, fig. 3, where it seems permeated by a system of canals. One end of body often more or less plainly radiate-striate, the usual distinction between the ectoplasm and endoplasm being here absent. This Prof. Biitschli regards as the attached (pronged) end. Also not rarely are seen a series 1Gabriel believed that the bladder does not furnish a suitable environment for metasporal development, consequently the latter must, he thinks, take place in or via the external world. In his opinion the myxosporidia living within the bladder represents not normally developing, but progressively degenerating forms. Such development as occurs within the bladder, by which apparently the way has been prepared for the replacement, at least within certain limits, of the perishing mother organisms, does not exclude the possibility of ripe spore-containers or free spores finding their way to the outer world and there under favorable (but as yet unknown) conditions developing. ‘This supposition, a necessary postulate, becomes a certainty when it is remembered that only thus [by active or passive migration] could the parasite have reached the bladder. Probably repeated, though perhaps (as indicated by the variations in their occurrence) not continuous, infection-immigrations occur. THE MYXOSPORIDIA, OR PSOROSPERMS OF FISHES. 285 of dark, longitudinal, ectoplasmic laminz separated by clear, somewhat reddish, apparently semifluid interlaminz. Not infrequently there exists a Similar clear reddish boundary layer between ectoplasm and endoplasm (Biitschli). Endoplasm consisting of colorless or yellowish myxoplasm, usually tinted reddish to reddish-brown (see Hematoidin below); distinguished from the ectoplasm by its color and by the presence of granules, globules, numerous small nuclei, vacuoles and inclusions (notably hematoidin erystals). Granules minute, arranged without order. Globules num- erous, irregularly scattered; in all probability fatty, being soluble in alcohol ;! containing hematoidin crystals. The older writers also inelude the nuclei under the term globules. Nuclei very numerous, small, with a dark surrounding membrane, granular contents, nucleolus and radiating fibrille (Biitschli). Pfeiffer remarks ? that these are to be referred back to the original single nucleus of the young myxosporidium. Vacnoles (apparently nonpulsating; indefinite as cegards number and position), are sometimes seen in forms with few granules. Hematoidin erystals: These were first observed by Lieberkiihn.® They were subsequently noted by Biitschli,* who rightly remarked that they must be derived from the biood of the host; i. e., that they are of extramyxosporidian origm. They occur in the fat globules, and are found free in the protoplasm only after solution of these globules by alcohol. They can be found from the smallest beginnings up to a more conspicuous size, the fat-globules then forming a proportionally slight covering for them (Biitschli). ; Pfeiffer > describes and figures a red blood corpuscle as included within the endoplasm. This he regards as the source of the hema- toidin crystals. He asserts that they are constantly present and that they occur free or within the fat-globules. He adds that if the myxo- sporidium has amceboidly surrounded these blood corpuscles and now consumes them, then in spite of the structure of the spores the Myxo- sporidia can no longer be regarded as Gregarines. Pseudopodia of 2 kinds: (1) Blunt, obtusely rounded, usually formed of ectoplasm alone, endoplasm taking part in formation only where the body as a whole forks. (2) Fine, hair-like or bristle-like, usually rigid, frequently branched, comparable to similar processes of many amcebe, frequently covering whole surface, not rarely, however, limited toa certain region of same (e. g., the end, as in certain amebe) ; 1 Biitschli, Bronn’s Thier-Reich, 1882, 1, p. 594. 2 Die Protozoen als Krankheitserreger, 1890, 1 ed., p. 44. 3 Miiller’s Archiy., 1854, p. 350; see also next footnote. 4 Ztschr. f. wiss. Zool., 1881, xxxv, p. 642; Bronn’s Thier-Reich, 1882, 1, p. 594. Biitschli credits their discovery to Lieberkiihn and Meissner. I infer from Lieber- kiihn’s statement, that Meissner’s results were communicated to him orally but were not published. 5 Die Protozoen als Krankheitserreger, 1890, 1 ed., p. 46; ib., 1892, 2ed., pp.17, 182, 286 REPORT OF THE COMMISSIONER OF FISH AND FISHERIES. both varieties may be retracted and again extruded; some of these processes are, however, optical illusions, being views in optical section of transverse ectoplasmic folds (Biitschli; Pfeiffer). Ameceboid movements!: Slow, well seen when examined in the urine of the fish; absent (from rapid death of myxosporidium) in water and many “indifferent” fluids, e. g., egg-albumen solution. Best seen in pike’s urine at 24° C.; the ectoplasm executes very extensiveamceboid movements, wrinklings, and foldings (Pfeiffer). Spore formation.2—Not confined to adult forms, but found in myxo- sporidia of all sizes. Thus few-spored large, and many-spored small myxosporidia are often seen (Gabriel). This occurrence at different times is explained by successive ripenings of the different individual myxosporidia composing the plasmode. Small round myxosporidia not yet entirely freed from the epithelial cell-remnants often contain 2 or more spores (Pfeiffer). Pansporoblast formation: This, the first step toward spore for- mation, takes place by the differentiation within the myxoplasm of a number of small, clear, transparent plasma-spheres ( pansporoblasts), each consisting of one of the many nuclei of the myxosporidium, together with a portion of the surrounding myxoplasm which it has attracted to it. Sometimes early, and in all cases later, each pansporoblast is surrounded by a thin dark membrane,’® and is found to contain a number of nuclei, usually 6. Pansporoblast-segmentation: Subsequently, instead of the pansporo- blast consisting, as originally, of the pansporoblast membrane contain- ing a single (usually sexanucleate) plasma-sphere, it comes to consist of the same membrane containing two‘ (usually trinucleate) plasma- 1! Gabriel (loc. cit.) gives a very detailed description of these movements, concluding that they are so complex and peculiar as to find no parallel with the Gregarines, and none appears admissible with the psendopodial movements of the Protozoa. Special emphasis is placed on the presence in the myxoplasm of a “‘thread-drawing” (Faden- ziehenden) substance, capable of emitting pseudopodioid processes, but incapable of retracting them. This, Gabriel asserts, finds a parallel only inmyxomycete plasmodes, of which it is an exclusive feature. Biitschli (1881, p. 640) has, however, observed the retraction of these processes. 2 Description Biitschli’s, unless otherwise stated. 3Pfeiffer confirms. Upon examining a myxosporidium in a dilute solution of eosin, or other stain, the spores stain only after rupture (by pressure on cover-glass) of this membrane. Gabriel dissents, regarding the pansporoblast as a ‘ wall-less vacuole, which first takes on the vesicular appearance described by Leydig at a later stage.” According to Gabriel the pansporoblast does not always persist to maturity, so that in the later stages it may be vainly sought. Gabriel was unable to trace a genetic relation between the ‘ granules” (? nuclei) of the myxosporidium and the spores, whence he concluded that the latter originate by a process, not of myxoplasmic integration but by one of secretion, the morphologic substratum of the sporigenous vacuoles being regarded as polysporogenetic centers strongly contrasted with the monosporogenetic centers of the Gregarines. 4 Spores in this species always developed in pairs (Biitschli). Spores not always, though usually, developed in pairs; such paired development may be absent among both developing and free spores (Gabriel). THE MYXOSPORIDIA, OR PSOROSPERMS OF FISHES. 287 hemispheres (sporoblasts, sens. strict.) which ultimately develop into 2 spores still contained within the pansporoblast membrane. Development of sporoblast to spore: The fate of the 3 nucleus-like bodies remains in doubt. The central one Biitschli observed to develop into the spore-“ nucleus.” The other two do not! (as would naturally be supposed) develop into the capsules; on the contrary, the 2 nuclei disappear, while the capsules appear in the protoplasm independently of them. Gabriel sometimes observed the sporoblasts (i. e., spores still within the pansporoblast membrane) to undergo a slow progressive con- traction to a globular shape, showing their membrane (presumably the future spore-shell) to be not yet rigid. A similar contraction was seen by the same observer in spores with partially disorganized shells. Spore.—Transversely and unequally biconvex-lenticular; length, 5 yu (z30/", Lieberkiihn; 4 to 6 y, Thélohan); breadth, 20 , or less (Biits- chli; 15 to 20 , Thélohan). Shell plainly visible, sharp contoured, rather thick, frequently showing a delicate antero-posterior striation; bivalve structure unknown, sulphuric acid producing no effect. Cap- sules 1 in each wing’; filaments 2 to 3 times the breadth of the spore. Sporoplasm almost completely filling the shell-cavity, extending even to the wings, there surrounding, as a thin layer, the capsules. Nuclei, 2 (fide Thélohan, letter 1893). Concerning them and the vacuole-like structure shown in Biitschli’s figures, M. Thélohan writes: The spore of Myxidium lieberkiihnii does not contain a vacuole. This is a fact of which I have assured myself many times. The dark streak shown in Biitschli’s figures belongs, without doubt, to the 2 nuclei of the plasmic mass which are often approximated, and, after the action of slightly elective stains, appear blended into a single mass. Exit of sporoplasm (Pfeiffer)—Easily observable by examination of bladder-mucus in urine of pike at 24°C. After 4 to 12 hours a scat- tered mass of burst shells are seen; also many spores not yet burst, showing the contents much more plainly separated than in fresh speci- mens. In someindividuals the sporoplasm is seen to flow ameeboidly out ‘ between the shells” (which are peculiarly unraveled) and wander away. Gabriel states that during the whole year that he studied this species he never saw the shell split to give exit to the sporoplasm. On the contrary, he describes the process substantially as follows: Shell undergoing a rather easily observable fluidification or resorption, its contour (heretefore, though thin and delicate, plainly perceptible), after a variable period, entirely disappearing. Sometimes during the resorption stage, always by time of iQn the contrary, Pfeiffer (Die Protozoen als Krankheitserreger, 1890, 1 ed., p. 98; 1891, 2 ed., p. 182), however, states that the capsules are formed from these 2 nuclei. 2Sometimes only 1 capsule at 1 “end,” very rarely 2 capsules together in the center (Lieberkiihn). Rarely ventricose monstrosities are seen with 2 capsules situated together at 1 ‘‘end” (Biitschli). Balbiani figures, beside the usual forms, others with 2 capsules in each wing. 288 REPORT OF THE COMMISSIONER OF FISH AND FISHERIES. disappearance of shell-contour, significant changes occur, involving capsules as well as sporoplasm, the capsules behaving throughout as integral parts of the “ proto- plasmic contents.” The sporoplasm, previously very transparent, bluish, rather strongly refringent and destitute of granules, becomes paler, sharply contoured granules rapidly appear in spots, and these very delicately contoured, round- elongate or irregular [formerly sporoplasmic, now become myxoplasmic] masses grow slowly or rapidly to small, strongly granulated plasmodes which already show some yellowish or reddish-yellow pigmented spots. Gabriel has also the following strange statement as to the subsequent course of development: Now it appears very peculiar that these 3 constantly present, morphologically individualized, delimited, constituent parts [sporoplasm and 2 capsules] should, in their further development, be restricted to a double course, viz, either fusing to a single protoplasmic mass or remaining in the original state of separation; in the latter case, falling apart by a rapidly progressing division, each into 2 (rarely more), approximately equal, parts. Growth of myxosporidium (Pfeiffer)—The young myxosporidium [heretofore termed the sporoplasm], immediately after its exit from the spore, penetrates into the interior of the red blood corpuscles and of the cells of the bladder epithelium. The infection of the former may be followed under the microscope. After 8 to 12 hours they show a noteworthy alteration, having become pale and, instead of 1 nucleus, containing 2, 3, or more nuclei. One of these nuclei is jagged, or wrinkled; the other (or others) is somewhat smaller, smooth, round, shining, and occupies (with reference to the jagged nucleus) a variable position. Hematoxylin stains the jagged nucleus dark, the smooth one bright. With the increasing growth of the smooth nucleus the jagged one rapidly falls to pieces, and its remnants become pressed against the -cell wall. Methylen blue and phloxin red stain the disrupted jagged nucleus black-blue, the other a uniform red. From these observations and the analogy of Lacerta and Testudo blood, the jagged nucleus is to be regarded as the cell nucleus, and the smooth nuclei as intruded myxosporidian germs. Here, too, the multiple infection (Mehrlingsin- Jektion) is repeated. Microscopic technique—Removed from their normal habitat, the myxosporidia rarely remain intact more than 24 hours, and then only in “indifferent” liquids, preferably (besides iodized serum) a 1:5 per cent sodium carbonate solution or a 0-5 per cent sodium chloride solution (Gabriel). Phloxin red and methylen blue stain the ectoplasm a sharply defined red, the entoplasm inclusions blue. This striking result ~ causes the myxosporidium to resemble a true rhizopod (Pfeiffer). Habitat and frequency.—Urinary bladder of Lucius lucius (pike). Most frequent and most highly developed in late summer and autumn; rare in winter; thence increasing in frequency. Size and age of host exert no influence (Gabriel). Free-floating in urine or attached (by pronged end). Biitschli observed young examples with one end partly surrounding an epithelial cell which had been torn away, thus present- ing a Gregarine-like mode of attachment. Observed by Lieberkiihn - THE MYXOSPORIDIA, OR PSOROSPERMS OF FISHES. 289 attached firmly to Distoma foliwm (frequently found in the pike’s blad- | der); also attached to other myxosporidia. Observed by Biitschli in December. All individuals of Zuwcius from the Rhine and Saar have myxospo- ridia in the bladder, while those from the E]be and Weser territory only exceptionally show them (Pfeiffer, 1891, p. 110). Perrier erroneously cites the habitat as the air bladder. Pathology (Pfeitter)—The coarser anatomical details can be seen (under 300 or 400 diameters) by carefully stretching a bladder tightly over a cork, placing a cover glass underneath, brief fixation, and hard- ening by alcohol and staining. Control experiments may be made by maceration in diluted acetic acid. The infection of the bladder was also followed by capillary cultures. Mucous membrane, when slightly affected, showing individual clusters of 4, 5, 100 or more epithelial cells infected with myxosporidia; thence all grades of hypertrophy (up to 10 to 30 times the normal size) can be traced. Hypertrophy of epithelial cells:. When slight, the cells are swollen, shining, apparently lobed. Pfeiffer failed to differentiate the nucleus and the intruder, probably owing to early succumbing of the nucleus. With greater hypertrophy the cells are filled with and overdistended by the parasites; subsequently, continued growth of the my xosporidium ruptures the cell membrane; the myxosporidium flows amceboidly out in grotesque shapes, and immediately differentiates its hyaline ectoplasm; rupture of cell membrane visible under the microscope. Hematoxylin or phloxinred-methylenblue stains a narrow-bordered, dark globule in the interior of the swollen epithelial cells; nucleus of latter invisible; largest cells indicating, by ragged coloring of contour, the degeneration of the epithelial remains. Hffects (of this species??).—Of late years dead pike and perch have frequently floated down the Mosel and the Rhine. It is doubtful’ whether the disease here is the same as the muscle infection of the barbel. According to a statement [unpublished, I infer] by Dr. T. W. Miiller in Greifswald, the spore found in the flesh of the pike is not the same as that of the barbel, but is formed upon the type of M. lieber- kithnit (Pfeiffer). Whether the pike and per chi in the Mosel die from myxosporidiosis is unknown. With the perch, fungous disease concurs (Ludwig).? 101. Myxidium ? ? incurvatum Thélohan, 1892. Compt. Rend. Acad. Sci. Paris, cxv, pp. 1093-1094. Cyst, probably none. Myxosporidium.—Small, feebly motile. Ectoplasm (in sections) very | clearly striate. me ndane the lobed, sometimes f>rming a bristly, shaggy | | coat, as in Myxidium lieberkiihnit. ‘Die Protozoen als Krankheitserreger, 1892, 2 ed., p. 105. ? Jahresber. d. rhein. Fisch.-Vereins Bonn, 1888, pp. 27, 28. 19 290 REPORT OF THE COMMISSIONER OF FISH AND FISHERIES. Spore.—Possessing only one plane of symmetry, viz, the valve- junction plane, differing in this respect from most other myxosporidian spores, Which have another such plane perpendicular to valve-junction plane. Form very remarkable, comparable to a pod whose acuminate extremities are oppositely directed; length (?),4 to5u; breadth (?), 8 to 94. Capsules, 1 at each end (or wing?), their long axes oblique and oppositely directed with reference to the long (transverse?) diameter of the spore. Filament extrusion very difficult of production; produced by nitric acid; length of filament, 124; sporoplasm nonvacuolate. Habitat.—Gall bladders of Onus tricirratus (=Motella tricirrata), Syngnathus (=Hntelurus) equoreus (pipefish), and Blennius pkolis, all from Roscoff; in B. pholis from Concarneau; in Siphostoma (= Syngna- thus) acus (pipefish) and Callionymus lyra. The description of this species is not sufficient, in the absence of figures, to warrant a positive opinion as toits generic affinities. Ihave attempted to construct from Thélohan’s description a diagram of the spore, but without success. The prevalent very loose use of such terms as ‘“‘ends,” “extremities,” “length,” “ breadth,” ete., renders them invalid for taxonomy, and the only course open seems to be to retain this provisionally in Myxidium, noting that in its bivalve structure it differs markedly from M. lieberkiihnii, the type species. 102. Myxidium? sp.incert. Pl. 47, fig. 6. Psorosperms of Raja batis, Leydig, 1851, Miiller’s Archiv., pp. 226, 234, pl. 8, fig. 4g; ib., Leuckart, 1852, Archiv. f. physiolog. Heilkde., x1, p. 4386, fig. 210. Myzidium? sp. Gurley, 1893, Bull. U. 8. Fish Com. for 1891, x1, p. 420. No description. The distinctness of this form from Chloromyxum incisum was recognized by Leydig (p. 234). Habitat,—Free in bile ducts of Raja batis L, (skate), THE MYXOSPORIDIA, OR PSOROSPERMS OF FISHES. 291 EXPLANATION OF PLATES, All figures copied are either of the same size as, or 14 times the size of, the figures from which they were copied; that is, in copying only 2 ratios were used, 1:1 and #:1. The relative sizes of the copied and the original figures are in every case indicated by the figures within the parentheses. All figures outside the parentheses indicate the total amplification from the specimens. For the derivation of any tigure, see table, pp. 131-134. PLATE 1. Figs. 1-4. Psorospermia sciene-uwmbre (after Robin. xX $). la. The convoluted string (cordon enroulé). X 14. 1b. Section of fig.la. xX 14. 2. Cells of variety 1. x 600. 8. Cells of variety 2. x 600. 4. Operculate cells of variety 3. x 600. IPA R es Figs. 1-2. Lithocystis schneideri (after Cuénot. X $). 1. Gregarine stage, with voluminous nucleus and clinorhombie crystals. 2a. Spore at the extremity of the tube, showing the truncated distal ava. rounded proximal extremities, and the sporozoites in course of formation. 2b. Fully developed spore containing 8 sporozoites. Fig. 3. Genus incert. sp. 3 (atter Miiller & Retzius. X 2). Spores from the diseaseé air bladder of Gadus morrhua. PLATE 3. Figs. 1-5. Balbiania rileyi (after Stiles. Xx 1). . A portion of the pectoral muscles of Anas boschas in the condition known as “measly duck.” . Longitudinal section of parasite (greatly enlarged). . Transverse section (greatly enlarged): ct, connective tissue cyst with nunier- ous nuclei; cu, cuticle of the parasite; m, sections of muscle. . Microtome section of meshes containing falciform bodies greatly enlarged. . Falciform bodies: a, stained, showing nucleus and vacuole; b, unstained. —_— oF Wh PLATE 4, Fig. la-m. Genus incert sp. 4 (after Valentin. x #). la. The original globular form. 1b-d. Different stages of the unrolling of the tail. le. A globule in which the separate dark granules appear to be inclosed in ~.wa- rate peduncles. 1f. Peduncle ideally enlarged. < 1lg-m. Various forms of the developed animal. Figs. 2-8. Genus incert. sp. 6 (after Schewiakoff. x 1). 2. Amcebiform stage. x 1500. 3-5. Enecystment. x 1500. 6. Cyst with 6 spores. x 1500. 7. Cyst thickly filled with spores. » 1500. 8. Plasmode proceeding from the fusion of 3 amebx. xX 1500. 292 REPORT OF THE COMMISSIONER OF FISH AND FISHERIES. PLATE 5. Figs. 1-11. Genus incert. sp. 6 (after Schewiakoff. x 1). 1-3. Developmental stages of the plasmode. x 1500. 4, Encystment. X 1500. 5. Cyst-tube with spores. > 1500. 6. A ruptured cyst with emerging spores. X 1500. 7. Spores sessile on the muscles. X 1500. 8. Individual spore. x 2600. 9. Small plasmatic corpuscles proceeding from the spores. X 2600. 10a-l. Transverse division of the spore; the nucleus dividing karyokinetically. x 2600. 1la-b. Conjectural conjugation stages of the spores. X 2600. PLATE 6. Fig. 1. Genus incert. sp. 9 (after Lieberkiihn in Biitschli. Xx 3). XX about 195. Myxosporidium from the gall bladder of Lota lota. Fig. 2. Genus incert. sp. 10 (after Lieberkiihn in Biitschli. Xx #). X about 195. Myxosporidium from branchiz of Lota lota with a very thick ectoplasm. Figs. 3-8. Genus incert. (‘‘ Myxosporidium”’) congri (after Perugia. X 1). 3-4. Two forms with “ vacuoles.” 6. An individual attached to a vegetable filament. PLATE 7. Figs. 1-3. Genus incert. sp. 12 (after Linton. X 1). 1. Notropis megalops with dermal cysts caused by ‘‘psorosperms.” XX 1}. 2. Spores from cysts, highly magnified. 2a. Vertical view of spores in caustic potash. 2a’. Same, more highly magnified. 2b. Transverse view of spore. 2b’. Same, more highly magnified. 2c. Spore treated with sulphuric acid. 3. Portion of thin section of cyst: a, pigment spot; b, granular protoplasm; c, spores; d, wall of cyst and dermis. xX about 150. Fig. 4. Genus incert. sp. 13 (after Lieberkiihn. X #). 4a. Spores from a subcutaneous cyst of Gasterosteus aculeatus. X 870. 4b-e. The same in different stages of development; b, spore with plain ‘‘nucleus” of usual size; ¢, d, with smaller ‘‘ nncleus;” e, ‘‘ nucleus” scarcely per- ceptible, the previously plain membrane no longer visible, animal mature. Fig. 5. Sarcosporidian spore of sheep with a ‘“‘cansnie” (after Pfeiffer. x 1). PLATE 8 Figs. 1-4. Genus incert. ( ‘‘ Myxosporidium™ ) bryozoides (after Korotneff. X 1). 1. Fie le of Alcyonella fungosa, with the spermatozooids and the parasite on them. x 350. 2. A parasite inclosed in an Alcyonella zooid. xX 350. 3,4. Creeping adults with nuclei and spores. X 750. PLATE 9. Figs. 1-4. Genus incert. (‘‘ Myxosporidium”) bryozoides (after Korotneff. Xx 1). la. Group of spermatoblasts, 2 of them containing very young stages of the parasite. x 900. 1b-d. Different stages in the conversion of a spermatoblast into a plasmode; cell nuclei and parasite nucleishown. X 900. le. Plasmode in which 1 daughter, and 2 granddaughter cell nuclei are visible. Nuclei of parasite numerous. 900. 2. A plasmode in which the cell nuclei are atrophying and possess a jagged con- tour. xX 900. 3. Spores in which vacuoles and urticant organs are to be distinguished. xX 900, 4. Nuclei of the parasite of plate 8, fig. 3. THE MYXOSPORIDIA, OR PSOROSPERMS OF FISHES. 293 PLATE 10. Figs. 1-3. Glugea anomala. la-h. (After Gluge. x 1.) ? la, ». Showing Gasterosteus aculeatus with tumors on sides of body and on tail. Sele 1c-e. Spores variously magnified. XX 255-840. 1f, g. The same “coagulated.” 1h. Cyst membrane. 2. Section showing, from above downward, subcutaneous connective tissue, cyst membrane, protoplasmic contents of cyst, and spores (after Thélohan. X 1). 3a-i. Group of spores: a, b, fresh; c-i, safranin stained; c, d, spores with 1 nucleus; e, f, with 2 nuclei; g, with 3; h, i, with 4 (after Thélohan. X 1). Figs. 4-5. Thelohania contejeani (after Henneguy and Thélohan). 4, Longitudinal section of diseased craytish muscle (X 1). 5a. Spores in sporophorous vesicle, and free (X #). 5b. Individual spore, more highly magnified (xX 2). Fig. 6. Thelohania octospora (after Henneguy. X 1). 6a. Sporophorous vesicle with spores. 6b. Individual spores. 6c. Longitudinal section of diseased muscle of Palawmon rectirostris, showing sporophorous vesicles between the separated fibrille. 6d. Portion of c more highly magnified. PLATE 11. Figs. 1-5. Thelohania octospora (after Henneguy and Thélohan. xX 1 except fig.5). 1. Transverse section of entire abdomen of a badly diseased Palemon rectirostris, showing, opposite the letters, the following: m,m, affected muscles; dt, diges- tive tube; n, nerve cord; cl, sections of the claws. 2. Longitudinal section of muscle showing the dissociation of the fibrillx. 3. Transverse section of diseased muscle. 4, A part of fig. 2, more highly magnified, showing fibrille with very clear stria- _ tion, and the sporophorous vesicles. 5a-d. Showing the spores: 6, in the fresh state showing the vacuole; a, ¢, d, after action of ether; a, with the filament partially, c and d with it com- pletely, extruded (xX $). PLATE 12. Figs. 1-2. Thelohania giardi (after Henneguy and Thélohan). 1. Spore formation (x #). la. Young pansporoblast. 1b. Pansporoblast whose nucleus has lost its membrane and presents itself under the form of an equatorial plate. 1c. Pansporoblast whose nucleus has segmented into 2. 1d. Pansporoblast the protoplasm of which has segmented into 2 uninucleate plasma hemispheres. le. Pansporoblast in the Iv stage; fresh state. 1f. Pansporoblast in the 1v stage, the augumentation of size of nuclei and change in disposition of chromatin preliminary to division. 1g. Pansporoblast in the Iv stage; nucleus in repose. 1h, i. Pansporoblast in the vit stage; different dispositions of the sporoblasts (the 8th in 7 is not represented, being hidden by the others). lz. Sporophorous vesicle inclosing 8 ripe spores. 1l, Pansporoblast inuclosing 4 normal spores, and 2 bodies each formed by the soldering together of 2 spores by their large ends: a, thickening of the pan- sporoblast membrane; b, spores soldered; s, normal spores. Im, n. 2 sporoblasts with crescentic nucleus. In the concavity of the latter, a clear vacuole. At asmall protoplasmic button projects into the vacuole. lo. Spores in fresh state showing at the large end a clear vacuole and at thesmall, a brilliant point corresponding to the capsule. 1p. Spores showing the vacuole and the lengitudinal shell-strie. 1g, r. Spores after action of sulphuric acid: gq, filament incompletely unrolled; r, filament completely unrolled. 294 REPORT OF THE COMMISSIONER OF FISH AND FISHERIES. PLaTE 12—Continued. Fig. 2. Pathological anatomy (x 1). Longitudinal section of diseased muscle of Crangou vulgaris, Showing fibrille with normal aspect preserved, and pan- sporoblasts in different stages of development, and spores. Fig. 3. Thelohania macrocystis (after Garbini. xX 1). 3a-c. Sporophorous vesicle and spores. 3d, Spores. de. A section of the diseased tissue. PLATE 15 Fig. 1. Myxobolus unicapsulatus (after Miiller. x 1). la, b. Vertical view of spores, showing the single capsule and the sporoplasm. le. Vertical view of spore, showing sporoplasm (and vacuole ?). ld. ‘Transverse view of spores. Fig. 2. AWyrobolus inequalis (after Miiller. 1). 2a. Vertical view, showing the unequal capsules and the sporoplasm. 2b. Transverse view. Fig. 3. Myxobolus piriformis and M. ellipsoides. Spores highly magnified from alee corpuscles of spleen of Tinca tinca (after Balbiani. x 1). 3A. Nos. 1, 2,6, Myxobolus piriformis? (see p. 211, footnote 1), showing ube elon- gate py riform outline and the single capsule. Nos. 3, 4,5, 7, Myxobolus ellipsoides? (See p. 211, footnote 1). 3B, C. Myxobolus piriformis or M, ellipsoides (which?). Fig. 4 . “‘Degenerated forms” from the spleen, liver, and kidney of Tinea tinca ‘(after Balbiani. x 3). 4a. Myxobolus ellipsoides? (see p. 211). 4b, c. Myxobolus piriformis (see p. 211). 4d-f. Myxobolus piriformis or M. ellipsoides (which?). PLATE 14. Figs. 1-3. Myxobolus brachycystis (after Remak). 1. Pigment follicle from spleen of Tinca tinea, containing 3 ‘‘ vesicles” [pansporo- blasts], each with a pyriform spore. To the right some of the pigment-con- taining vesicles which fill the cyst. (All fide Remak. ~ 1). 5. Branchial lamella of Mugil auratus with cysts. « 6. Vertical view of spore. Fig. 7. Myxobolus sp. 40 (after Lieberkiihn in Biitschli. x 3). X about 1050. Ta. Vertical view. 7b. Transverse view. Figs. 8a-d. Myxobolus oviformis. From cyst of fins of Gobio gobio; safranin and gen- tian violet (after Thélohan. xX 1). 8b. Vertical view of spore showing 1 nucleus. 8c. Same, with 2 nuclei. 8d. Same, with 3 nuclei. ® THE MYXOSPORIDIA, OR PSOROSPERMS OF FISHES. 295 PLATE 15. Figs. 1-6. Myxobolus? sp. 41 (after Lieberkiihn; except 1). 1. Two spores inclosed in the pansporoblast membrane (after Biitschli. x $). < about 1050. 2. Cyst from branchiz of Gasterosteus aculeatus (xX 1). 3. Free spores from cyst of fig. 2. (x 3.) xX 675. 4. Another cyst in which spore formation has taken place (x1). x 330. 5. Another cyst (X 1). xX 220. 6a-c. ‘‘ Different forms [? developmental stages] of spores” of this species (x 3.) Fig. 7a-c. Myxobolus sp. 44. 7a. Transverse view of spore (after Lieberkiihn in Biitschli. x 3). x 1850. 7b. Spore with valves separating, giving exit to sporoplasm (after Lieberkiihn. Sos) oe wooO: 7c. Sporoplasm undergoing amceboid movements (after Lieberkiihn. x %). xX 1350. PLATE 16. Figs. 1-6. Myxobolus miilleri (after Biitschli. x 1, except fig. 1). 1. Two branchial lamelle of a cyprinoid, one containing a conspicuous myxo- sporidium. c. The cartilaginous rod supporting the lamella (x #). 2. A portion of the membrane of fig. 4, more strongly magnified, showing ‘‘ nu- cler.7 3a. Transverse view of spore. 3b. Transverse view of 2 separated valves. 4, An isolated small myxosporidium with its membrane. 5. Nuclei of the myxosporidium. 6. A series showing the developmental stages of the spore. 6a. Sporoblast which has segmented into the 2 protocysts and the protosporo- plasm. b-c. The segments have oriented themselves; the protocysts show beginning capsule formation. d,e. Later stages of capsule formation. In e orientation of the capsules has taken place. PLATE OLY. Figs. 1-7. Myxobolus miillert (after Biitschli. x 1). la. Vertical view; showing capsules, sporoplasm, vacuole and pericornual nuclei. 1b. Vertical view; showing capsules, ‘‘globules,” sporoplasin, and vacuole. -le. Vertical view, showing a common focus-appearance (?focus-illusion), the pericornual nuclei apparently attached to the posterior extremity of the capsules. Biitschli says the sporoplasm is ‘‘ contracted ” and hence the vac- uole is invisible. 2. Transverse view of spore after action of concentrated sulphuric acid; the filaments are extruded and the valves are beginning to gape apart. 3. Vertical view of spore with extruded filaments, sporoplasm, and ‘‘ globules.” 4a-d. ‘‘Abnormal” tailed spores; c, spore with 3 capsules. 5. A separated valve, viewed transversely. 6. Spore with filaments extruded by pressure. 7a. Capsule not yet completely developed, with the filament extruded. 7b. A fully-developed capsule with extruded filament. PLATE 18. Figs. 1, 2. Myrobolus piriformis and M. ellipsoides (after Balbiani. X 1). ~ 1. Section of splenic artery of Tinca tinca, showing on the branches Malpighian corpuscles, most of them containing Myxosporidia. 2. The same, more highly magnified, showing well-developed bicapsulate forms (M., ellipsoides) and pyriform unicapsulate or noncapsulate and degenerate forms (M. piriformis). 296 REPORT OF THE COMMISSIONER OF FISH AND FISHERIES. PLATE 19. Fig. 1. Myxobolus bicostatus (after Lieberkiihn in Biitschli. x 3). Vertical view of spore showing the 2 oblique ridges on the shell, the capsules, and the sporoplasm. Figs. 2-8. Myxobolus ellipsoides. 2,3. Pfeiffer’s copies of figs. la, 1b of plate 20 (x 1). 4. Mesenteric artery of Tincatinca with sessile or pedunculate cysts developed at the expense of the connective tissue coat of the vessel. Cyst contents myxosporidia, alone or with imbedded brown (hxematoidin-colored) gran- ular matter (after Balbiani. X 1). 5. Section of diseased air bladder of 7. tinca, showing spores and, at the left-hand margin, the internal epithelial surface of the air bladder. Borax carmine, gentian violet (after Thélohan. X1). 6. Section of cyst of branchiz of T. tinca; showing in order, from above down- ward, the branchial epithelium, cyst membrane, myxoplasm, spores, and the nuclei of the last. Picro-carmine and gentian violet (after Thélohan. x 1). 7. Transverse section of air bladder; carmine, celloidin (after Pfeiffer. x 1). x 100. 8. Portion of fig.7 (after Pfeiffer. x 1). Xx 400. On the wall of the cyst the younger, still uninuclear, parasites; to the right trinucleate sporoblasts. PLATE 20. Figs. 1-4. Myxobolus ellipsoides. ; la-c. Myxosporidium and cyst from fins of Tinca tinca, with spores in course of development (after Balbiani. x 1). la. Small myxosporidium containing only nuclei. 1b. More advanced stage. le. Large encysted myxosporidium containing numerous spores, mostly mature. 2a-c. Three stages in spore formation, showing paired development of spores in amass of homogeneous plasma, and the spores contained at maturity in a vesicle (after Balbiani. x 3). 3a-c. Spores from air bladder of T. tincashowing ribbons (after Balbiani. #). 3a, b. Spores united by the ribbons, the sporoplasm rolled into a ball, and the “accessory ” capsules. 3c. Isolated spore with extended ribbons; capsules empty; sporoplasm in a ball. 4a-e. Spores from the air bladder of 7. tinca, showing different stages of devel- opment of the nuclei; carmine, gentian violet (after Thélohan. X 1). 4a. Spore with 1 nucleus. 4b. Spore with 2 nuclei. 4c. Spore with 3 nuclei. Ad, e. Spores with 4 nuclei. PLATE 21. Figs. 1,2. Myxobolus ellipsoides. la-h. (After Balbiani. x 3.) la. Vertical view of spore, showing pericornual nuclei and anteriorly a “‘olobule.” 1b. Transverse view, showing the equal convexity of the valves and the equality of the two ends of the spore. ! le. Vertical view of spore, showing capsules with filaments extruded, pericornual nuclei, anteriorly a ‘‘globule,” and posteriorly the sporoplasm (? contracted under the action of reagents). 1d. Spore in vertical view, showing ribbons, and sporoplasm in act of exit. le. Capsule with filament coiled. 1f-h. Different degrees of extrusion of filament. 2a-e. Sporoplasm after exit, showing changes of form (after Balbiani. x $). n, “nucleus” [ ? vacuole]. Fig. 3. “Degenerate processes of the*spores of Tinca tinca with 3, with 2 approxi- mated, with 1 capsule, with candiform drawing out of one pole, with approximation to the sarcosporidian germs. The same are found in the gall bladder of the tench and in aneurisms on the splenic artery” (after Pfeiffer. xeb) ex C00: d. Myxobolus ellipsoides (apparently ; remainder indeterminate). Fig. 4a-b. Myxobolus ellipsoides?? ‘Spores inclosed in a cell [?pansporoblast] mem- brane becoming stained at the moment of birth, with eosin” (after and jide Pieter. ><). = #). 7a. Vertical view of spore, showing pericornual nuclei. 7b. Vertical view of spore, showing capsules with filaments extruded, and the sporoplasm with its cornua, and the supero- and infero-anterior margins. PLATE 29, Fig. la-d. Myxrobolus transovalis (original). la-c. Vertical view showing outline, capsules, sporoplasm, vacuole, and nuclei. Hydrochloric acid alcohol carmine. 1d. Transverse view showing equal convexity of valves, and the narrow ridge. Figs. 2-7. Myxobolus? merlucit (atter Perugia. » 1). 2-6. Various forms of the myxosporidinm; showing also the spores, 7. Two spores making their exit from the myxosporidium. Fig. 8. Myxobolus sp. 67 (after v. d. Borne. xX 1). 8a. Group of spores. 8b, Leuciscus rutilus with the myxosporidian tumors, PLATE 30. Fig. la-q. Myzxobolus cf. creplini showing different views of spores (after Weltner. x1). ap, X 528; g, x 720. All were drawn with Abbe camera; m, n, are optical sections at the level of posterior end of capsules; g, separate cap- sules; one dull and with filament still coiled; the other transparent with filament extruded. PLATE 31. Fig. la-e. Myxobolus 2? zschokkei (after Zschokke, Schieck Oc. 2, Obj.7. x 3). Vertical views of spores with extruded ‘‘tails”; also the capsules (?). Fig. 2. Myxobolus medius and Chloromyxum elegans. Section of tube of kidney of Pygosteus pungitius, showing spores of the two species surrounded by epi- thelium of tube. Borax carmine and gentian violet (after Thélohan. Bg 1D) Fig. 3. Myxobolus medius (original enlargement from preceding. X about 4). Fig. 4. Myxobolus medius. Spore in pansporoblast (after Thélohan. x 1). Fig. 5. Myxobolus strongylurus (after Miiller. x 1). 5a. Vertical view. 5b. Transverse view. - * For 6 and c, see Ohloromyxum dujardini, plate 40, fig. 4. 300 REPORT OF THE COMMISSIONER OF FISH AND FISHERIES. PLATE 32. Figs. 1, 2. Myxobolus creplini. la-e. (After Creplin. xX 1.) la, b. Vertical view of spores. lc. Transverse view. 1d. Vertical view (of an illusory appearance? See p.249). The larger size of this figure merely represents higher magnification. le. Transverse view of spore with the valves gaping anteriorly. 2. Vertical view of spore (after Leuckart. x 1). Figs. 3, 4. Myxobolus monurus (after Ryder. X 8). 3a. Aphredoderus sayanus with tumors. 3b. Cyst, much enlarged. 3c. Vertical views of 2 spores, showing capsules and tails. 4b-d. * Vertical views of spores. Fig. 5. Myxobolus macrurus (original). Vertical view of spore, showing capsules, sporoplasm with vacuole and 3 nuclei (2 the pericornual), and the full length of the tail (about 4 times that of the body). PLATE 33. Figs. 1-4. Myxobolus macrurus (original). 1. Transverse view showing, on the right side, the more convex superior valve and the greater anterior projection of the supero-median cornu; on the left, the less convex inferior valve; along the center, the narrow ridge. 2. Vertical view, showing the vacuole and nuclei. ; 3. The same, showing aiso the beading of the tail after the action of iodine. 4, A tail separated from the body by iodine. Figs. 5-8. Myxobolus ef. linearis (original). 5. Vertical view, showing divergence of valves under action of sulphuric acid, and the tail separating into a superior and an inferior half. 6. Transverse view, showing supero-inferior syminetry and narrow ridge. 7. Vertical view of unstained spore, showing vacuole. 8a-d. Vertical views of spores, showing vacuole, nuclei, and flexibility of tail. Hydrochloric acid alcohol carmine. PLATE 34 Figs. 1-4. Myxobolus psorospermicus. 1. From branchie of Perca fluviatilis (after Lieberkiihn in Biitschli. x #). x about 975. la. Vertical view of spore with a simple tail. 1b. Transverse view of same. le. Vertical view of spore with a double tail. 2a-c. From a branchial cyst of P. fluviatilis, showing capsules, sporoplasm, vacuole, and nuclei. a, with 1 nucleus; b, with 2 nuclei; ¢, with 3 nuclei. Carmine and gentian violet (after Thélohan. x 1). 3a-d. Spores from Perca fluviatilis (after Balbiani. xX $). 3a. Vertical view. 3b. Transverse view of spore with 2 tails. 3c. Form slightly abnormal. 3d. Vertical view of spore, showing capsule with filaments extrudea, cornua o- sporoplasm, and pericornual nuclei. 4. Spores from Lucius lucius (after Balbiani. x $). 4a. Vertical view. 4b. Transverse view. 4c. Spore with valves separating to permit exit of sporoplasm 4d. Vertical view showing filaments extruded, and cornua of sporoplasm. PLATE 35, Figs. 1-7. Myxobolus kolesnikovi (after Kolesnikoff). 1-6. Cysts (xX 1). : 7a-o. Spores showing extruded filaments and single and double tails (xX $). 7g. Separated capsule with extruded filament. * No a to this figure. THE MYXOSPORIDIA, OR PSOROSPERMS OF FISHES. 301 PLATE 36. la. Showing cyst contents, consisting of spores and finely granular matter. 1b. Individual spores. le. Aberrant spores seen only once among the contents of a cyst. 1d. Group of spores; vertical and transverse views. Fig. 2. Myzobolus linearis. Group of spores showing the narrow outline and the single and double tails (after Miiller. x1). Fig.3. Myxobolus sp. 61. Rare forms of spores reproduced among tailed forms, from plate 28, fig. 6. Fig.4. Myxobolus diplurus (after Lieberkiihn in Biitschli. Xx $). Xx about 1050. Vertical view showing posterior position of capsules and double tail. Fig. 1. Myxobolus schizurus (after Miiller. x 1). PLATE 37. Fig. la-f. Chloromyxum incisum (after Leydig. X 1). la. Myxosporidium without pansporoblasts. 1b. Same with 1 pansporoblast, but no spores. 1c, d. Same with sporoblasts. le, f. Same with fully developed spores showing the crenate posterior border. Fig. 2-7. Chloromyxum leydigii (after Perugia. X 1). 2. The myxosporidium. 3. The same, containing numerous spores. 4. The same, giving exit to 3 monosporophorous pansporoblasts. 5, 6. Pansporoblasts with spores; in fig. 5 the spores with 4 capsules, 7. Spore giving exit to the sporoplasm. PLATE 38. Figs. 1, 2. Chloromyrum leydigii (after Leydig. X #). 1. From gall bladder of Raja batis. 1a, ad. Myxosporidia of various sizes without pansporoblasts. 1b, e. Myxosporidia, showing (b) pansporoblasts and various stages in spore formation; also outline of spore. 1f. Longitudinal (‘‘end”) view of spore, showing the 4 capsules. 2a-c. From gall bladder of Squalus acanthias. Myxosporidia without pansporo- blasts. PLATE 39. Figs. 1-3. Chloromyxum leydigii. 1. Myxosporidia from gall bladder of Torpedo torpedo (after Leydig. x $). la. Without pansporoblasts. 1b. With pansporoblasts and spores. 1c. With pansporoblast and sporoblast. 2a-b. Myxosporidia from gall bladder of Scylliorhinus canicula (after Leydig. xX $). 2a,,a.. Myxosporidia without pansporoblasts. 2b. Myxosporidium with 12 pansporoblasts, each containing 1 spore. 3. Myxosporidium. This figure appears to be generalized from figures a, a2, of the preceding (after Leuckart. 1). Fig. 4. Chloromyxum fluviatile (atter Thélohan. x3). Vertical view showing the capsules in 2 lateral pairs, the nonvacuolate sporoplasm, the vertical position of the ridge, and the minute spines on the shell. Figs. 5,6. Chloromyxum mucronatum. 5a, b. From urinary bladder of Lota lota (after Lieberkiihn. x 3). 5a. Longitudinal view of spore, showing the 4 capsules. 5b. Vertical view showing the mucronate anterior extremity, capsules, and sporoplasm. 6. From Lota lota (after Balbiani. xX 3). 6a. Vertical view showing capsules, pericornual nuclei, and vertical position of the ridge. 6b. The same; also beginning of valve separation. 6c. The same; also corkscrew extrusion of tilaments, 302 REPORT OF THE COMMISSIONER OF FISH AND FISHERIES. PLATE 40. Fig. 1a-c. Chloromyxrum elegans (original enlargement from plate 31, fig. 2. x about 3). Three views of spores, showing outline, ridge, and capsules. Fig. 2a-b. Chloromyrum perlatum (after Balbiani. X 3). Vertical views of spores showing outline, capsules (b with filaments extruded), and vertical position of ridge. Fig. 3. Chloromyxum sp. 91. Vertical (?) view of spore from the ovary of Lota lota — (after Biitschli. x $). Xx about 900. Figs. 4-7. Chloromyxum dujardini. 4. From Leuciscus rutilus (after Miiller. X1). 4b. Vertical views. 4c. Transverse views. 5. Myxosporidium from branchie of Leuciscus erythrophthalmus (after Dujardin. is) en icee 6. Spore showing outline and capsules; from L. erythrophthalmus (after Dujar- Glin, 4 IDs Se ete 7. Free ameeboid myxosporidium from a branchial lamella of Leuciscus erythroph- thalmus (atter Biitschli xX $3). X about 30. Fig. 8. Chloronyxum ohlmacheri (after Ohlmacher, Leitz obj. 3, 0c. 4. x1). From photomicrograph of section of kidney; showing at a, and elsewhere, myxo- sporidian masses in the tubules; at b extravasated blood corpuscles; at ca large blood vessel filled with blood corpuscles. Fuchsin and iodine green. PLaTE 41. Figs. 1-3. Chloromyxum ohlmacheri. 1. Spores (after OhImacher. Leitz pantachromatic oflimm.2mm.,oc. 4. x1). la. Vertical view of spore, showing capsules with extruded filaments. Camera lucida; Babes’s anilin water safranin. 1b. Vertical view showing capsules, spiral-coil structure of shell, and vertical position of ridge. le. Striew are seen ‘‘running nearly meridionally”; at one ‘“‘side” of spore a capsule ‘‘appears in the act of escaping through a rent” in the shell. 1d. Fragment of shell in which the stri# appear to correspond to ridges encircling the shell. 2. Kidney tubule, inclosing 3 spores, showing capsules and sporoplasm, the lat- ter structure being represented in 1 spore as divided into 2 lateral halves. (An error; see p. 270.) Pfitzner’s alcoholic safranin (after Oblmacher; camera lucida; Leitz pantachromatic 3 mm., oc. 4. 1). 3. Diagrammatic figure of spore; a, shell; b, sporoplasm; c, capsule; d, posterior extremity of ridge and spore; e, ridge; jf, anterior extremity of ridge and spore; g, filaments, much shortened; a, b, c, are on the left side of spore; eon the right. (After Whinery. X 1). Fig. 4. Ceratomyxa spherulosa. Spore showing hollow-cone valves, vertical ridge, and valve-junction plane, capsules, and (spo.) the unilateral sporoplasm, and (x) pale corpuscles of indeterminate nature (after Thélohan. X #). PLATE 42. Figs. 1-10. Cystodiscus immersus (after Lutz. X 1). 1. Gall bladder of Bufo aqua with myxosporidium disks shining through. X 1. 2. Portion of mediura-sized specimen with large number of spores. X about 70. 3. The same; the ruptured ectoplasm permitting the exit of the contents in the form of vesicles. X about 70. 4, Ripe spore-pairs. 5. Vertical (?) view of mature spores, showing ridge. 6. Longitudinal (?) view of same. 7. Spore with extruded filaments, showing the striw of the shell. 8. Spore with valves separated. 9. Developmental condition of spore. 10. Mature spore; contents made plain by carmine; containing micrococcoid granules. x about 600. Figs. 11-13. Cystodiscus ?% diploxys (after Balbiani). 11, 12. Spherical cysts in process of spore formation (X 1). x 85. 13. Spores from the cysts (x #). X about 1500, 13a. Vertical view. 13b, c. Transverse views. : i THE MYXOSPORIDIA, OR PSOROSPERMS OF FISHES. 303 PLATE 43. Figs. 1-5. Myridium lieberkiihnii. 1. Myxosporidia (after Lieberkiihn. x 1). la. Showing the granule-free, pronged end by which attachment is effected, and a pansporoblast containing 2 spores. x 330. 1b. Myxosporidium which has mostly broken up into pansporoblasts. x 900. 2. Specimen covered with transverse wrinkle-like elevations; at one end some pseudopodia (after Biitschli. x #). x 160. 3. Three successive stages in the development of clear ectoplasmic pseudopodia at one end of a large myxosporidium (after Biitschli. x1). 4, Small myxosporidium attached to a nucleated bladder cell (after Biitschli. x2eeeae 175 media, Henneguya; see Myxobolus medius. medius, Myxobolus ................22-.---- 248 Merlangus merlangus.....-.....-.......... 173 AOHIMTCCUMKOLEOT) 2-02 5<-oSea coca sew adeeccas 242 Mierlnecins (error) 2 +--.- INDEX TO MYXOSPORIDIA. he Page. Page Bim-mqualis-(GPLOL). jc < ee ets MgO 71 Mey xos paride: (@LC0L) -< emae oe oes eee ie Miy-xO8 POFI(IA ps - sa a= = sae eee 71,73 dispersal, necessity of, and IMCANS fOr. saecee seas 90 distribution of, geographical .-.:.<..2.: 110 OLP ANAL -s 0a eee 105, 108 SOASONBLS << .e > aaa ee 110 ZOOLOPI CHIL Ss tema sere 100 effects of, on host -.. 118, 194, 197, 200, 204, 231, 248, 270, 289 epidemics produced by... 197, 231 fusion of; see Plasmodes. My KOSPOTIGI Of seca nasal Cees oe ae 206 Miu sosporidium:+ 20. (Sacceme cate ere 120 description 0f --24s2ee2-4- 73, 7d taxonomic value of.....--. 112 ‘EMEyxosporidiam”? 4 Shek seenseaer 182, 187, 206 bryozo0idesic 532 sncoee se 187 GONGT) Ff... 0282 ean eee 110, 182 merlucii; see Myxobolus merlucii. mugilis; see Myxobolus MUSILIS Sos ck seis sees 213 plagiostomi; see Myxo- bolus leydigii. ING GeLS cite do tame F258 nacuiseon es emer ontae 192 narce, lorpedo; see Torpedo torpedo. narke, Torpedo; see Torpedo torpedo. Nematocysts, homology of, with capsules. 89,90 Nosema anomala; see Glugea anomala-.... 192 DOMDY Cis oe soe oes wosee eee eee 192 Nuclei, capsulogenous; see Nuclei, pericor- nual. c ' division of...... icp cteceesee LTOPISTeCOR IV REPORT OF THE COMMISSIONER OF FISH AND FISHERIES. Page. Wuclei in Myxobolus ------.2-----0 0322-5 208 Of My SOS pore Secon wee ase anes 76 OL SPOLG =o. ser one as eee pene eee 92 pericommual yes) 5- okwem eee ea 82, 209 as aspecifie character 117, 210 obesus; Mayxobolusss-.i- <= ee bieloee eran 239 Oblowens, Mysobolus ce seeseeeew esas = 234 octospora, Thelohania...........----.---- 177, 197 ohimacheri, Chloromyxum. ...---- oa 267 Spore, orientation of, in Cystodiscide ..... 278 Ovary “Species tound ane =s.65 - sete aie 107 DVALONMIIS eVby XO DOMIS eee ee ee aecss seis 214 Pansporoblash seasweseicecee= sees 80, 81, 120, 121 Pa thOlO Sys es eecehs cece = alee dee esi 117, 197, 222, 228 Percariuaviatilis(Orror) sc. 2-5. besc-ceceee 217 Perch, yellow; sce Perea fluviatilis. EMiCVAtICESPACO 2... se-sac ccs) sa cine decet 120 perlatus, Myxobolus; see Chloromyxum perlatum. Pfeiffer, species described by..-.--.-------- 137 Phenocystes, definition of generic charac- HOLA I eaet Salah ise = cents aoe Owe ca eles 113, 205 phoxinus, Cyprinus; see Phoxinus phox- inus. ; Pigment, in the Myxosporidia ..-..--. 76, 258, 277 Pike; see Lucius lucius. Pike perch; see Stizostedion lucioperca and Aphredoderus sayanus. IMG OGOS(OLEDD) res ste eee te cbse 212 Pimelodus blochii: see Pimelodus clarias. sebze; see Rhamdia seb. Pipefish: see Siphostoma and Syngnathus. Minitoumis: Myxobolus,- 2 2ce-. lo.s2-sssecee- 211 plagiostomi, ‘‘ Myxosporidium”’; see Chloro- myxum leydigii. alanies Oh SY MIN CLL veri Jo ees anise eae ce ae a0 120 Plasmatic (and plasmic) mass; see Sporo- plasm. Plasmode formation......-.-.-.. 75, 99, 177, 188, 227 Platystoma fasciatum; see Pseudoplatys- toma fasciatum. PNAS TOPNOLD) owe tcl agra’ cae te wsjcematee aus 194 spore formation as a generic Character Off: - = a eese 2 sees 90 dichromophilism of, literature of..-. 269 Ohlmacher on.. 268 general description of...--..+...--.. 74 Spore, orientation of, in Ceratomyxa-....... 274 Ses sey. Page. Spore, taxonomic value of?..:\--.:-.2-<2--:. 112 Spore form as a specific character......--... 117 asserted ANCOUStANGY Of. .<0et orn $8, 99 MMOLE OLMAviONe ses tee sec css ee ae TOR 201 as a generic character...--- 79 Spore symmetry, taxonomic valve of....-- sey lates Spore topography, taxonomic valne of..-.. 114 ~ Spores, abnormal, degenerated, and ‘‘mon- SUOUS”, x52 ia kee eee es 224 constricted in middle 180, 203 SCOR AL. Socliggo G5 anne eee ae $9 SPOMGient sees ccs coon sate FEROS A ESB AS = 98 SHORES i, gh 5555 e5 cee ae ee 82, 121 SURGE ik 0a Gee ee 121 Sporophorous) Vesicle = .-.2...0.......-5--- 202 SPCR) SSR Rees es ae 74, 92, 121, 251 GRiiGH. se sep saeco poe Sees ae 93 Sporozoa, definition of class...........---. 71 Gregarinida proposed as type OLGSr 2 Of payee osie wees ee alerts hore 71 Squalius, subgenus of Leuciscus. Squatina angelus; see Squatina squatina. Pr GOGO C1tEd ea. acja- fiancee ae coat stews 172 Stickleback; see Gasterosteus aculeatus. 9-spined; see Pygosteus pun- gitius, strenuus, Cyclops, parasite of .............. 176 strongsylura (error) .-----..--- Sap eeEor 249 strongylurus, Myxobolus .......:--.------- 249 POPE CMCTAMUPACH I. Am toc Joona cea cone seceee lllals “SQuPlPin ccs 5 Se ep SN 122 youayuTs, parasite of .-...--.02.-2--s---56 137 Symmetry of spore..-¥......-...----- soaecn alle! MIN EMOhs nea aise eee cles 120 Synenathus acus;*see Siphostoma acus. Synonymy, method of compilation of-.-.... 66 WT A Re ee et er 207, 245, 250, 254 PevelopmentiOt 2.28. see one SS Oe caiman e 82 supposed formation by approximation GME HONEHtES| S254 sss 2. tees s sence. 224 taxonomic value of ........ miles 5) 117, 207, 245 Ravimuscleswatrophiy ofs. (22.2. [2.5 <2 172,173 Yench; see inca tinea. Vesticle, absence of Myxosporidia from.... 106 Tetraonchus vanbenedenii...............-. 106 Thélohan: cited: ..-.s2--.-.. 211, 216, 228, 248, 266, 273, 287 TO MYXOSPORIDIA. Vv Page. Thelohaniaiosace ene seers see bearers aCe 195 spore formation as a generic character Ofs22.fonssacee ease : 80 tinca, Cyprinus; see Tinca tinca. Tincachrysitis; see Tinea tinea. tinca,synonymy of formshabitanton. 221 vulgaris; see Tinca tinea. Toads; see Bufo and Cystignathus. asserted existence of Myxosporidia Inkidney Of = sc «a2 oer eee 135 Torpedo narke; see Torpedo torpedo. transovalis, Myxobolus ......-.-..---..-- -- 242 tricirrata, Motella; see Onus tricirratus ... 282 Trout, brown; see Salmo fario. Trygon vulgaris; see Dasyatis pastinica. FLT Sy DATO GIN Hiays arele atten aielel= alae ele ete aime eae O4! tuberculatus, Catostomus; see Erimyzon sucetta oblongus. Twinned vesicles; see Capsule. typicalis, Pleistophora ...........-.-.--- Bee wise UMbLa SClBNa =» = soacGeac os as es Jeost d3es33 166 unicapsulatus, Myxobolus ....-....---.--- soe ee illt) Vacuole, aniodinophile -....-......-.-.---- 2 Contractile = cs. 2 9-55. -= eae ees 181 iodinophile 92, 109, 208 organal distribution of 109 Vacuoles in myxosporidium......-.---.---- 76 Valentin, species described by.-.-.-:-.-.------ 174 Vallentin, species described by-...-.--..--- - 135 Walivest -ocine catcets ose ee aia als, atatteietersee = Sake ae 122 viridana, Pyralis; see Tortrix viridana, viridiana, Pyralis; see Tortrix viridana. vulgaris, Acanthias; see Squalus acanthias; Acerina; see Acerina cernua. Barbus; see Barbus barbus. Conger; see Leptocephalus conger. Lota; sce Lota lota. Merlucius; see M. merlucius. Spinax; see Squalus acanthias. Tinea; see Tinca tinea. Trygon; see Dasyatis pastinica, Welt; see Ridge. Whitefish, see Coregonus. Wraerzejsici cited) << -a-e-sese-e see nse Sales Zacharias cited ........--- Sebo boosa eae ee 135 ZSUEIN CLUE Ceaiars x nate eee eee ee see 71 zschokkei, Myxobolus ....-.-- penis See are. ee PLATE 1. Myxosporidia. 1892. Report U.S F.C. Fig. 4. PLATE 2. C. 1892, Myxosporidia. Report U. S. F. Fig. 2. Ta ae St a, ae eae . PLATE 3. Myxosporidia. Report U. S. F. C. 1892. : ae PLATE 4. Myxosporidia. Report U. S. F, C. 1892. Fig. 8. Fig. 2. Fig. 1. Fig. 5. Fig. 4. Fig. 3. Fig. 6. Fig. 7. wi stor ar ies , id : U Report U. S. F. C. 1892. Myxosporidia. PLATE 5. Fig. 2. PLATE 6. Myxosporidia. Siew e92. Report U g. 2. i LN ° s Tig. 5. Report U.S. F.C, 1892. Myxosporidia. Fig. 4. PLATE 15. PLATE 16. Myxosporidia. Report U. S. F. C. 1892. a Fig. 3. Fig. 1. Fig. 6. ies, Fig. 5 Fig. 4. Ti ee ab 7 Mae , Pik es ’ " j Si a figs anys Ww en Wie A) PA ee lie Myxosporidia, Report U. S. F. C. 1892. Fig. 1. Fig. TS sia ol pee SSE TSS, Fig. 6. ET M ty) ing ns 5 > mayen Leek PLATE 18. Myxosporidia. Report U. S. F. C. 1892. g x a Che€ RE cD Bl Y Yi Ss Seen os PLATE 47. Myxosporidia. Report U. S. F. C. 1892. s 20 fe Fig. 1. Fig. 2. Fig. 5. Fig. 4. Fig. 3. ae Tho sg : : a Pa per hes ety | Hh Worse : n ‘pag a ses a in TY 4 Fan ("= \ > eld aty anae CssnnyoAbase rT tater eye yp NHL! | ” 1h | [ LTO a dina Aleit ia a 7.4 : azal* 24 (en en a we 4 at bee ‘ ar\ ‘ ¥ ’ an he G pdr PRPC Ane ‘ o4vs+ eabeenem soappsne nant? in Qprenne Pete A. aanayypree®? phen: Wee tpn AARee Prat YOO ofhan LARAMane Ra dtnts. rho anne anPanpoh aN asa on Molly tall olf Uo =n npel conan s adaa Fe : ny nyt \ ; ATT | 1 Yn rE e! Ringe} or OA mA Rae ae | Bae i = pals. | | he dee. Pine Ve We Q'\y% 26 > cage Hid eee ie «Bre Say veces dig a be CIT] ry ry i va) “inae. ta rh aru Naya 4. TE *'6 Toy f tae. Yr 3 oe oap athe... phos yey Y 4 “Ny a ( 4 Meea, p y N POAaAAR x ‘> ty ty vv pet 7 mw » oy Nan of Sapr0> dora t, don ddedatd Vor erect Pee Nn. ane Ne Creat PEA , Perens ttecnanrn Dida aNIRAARasa nas Bay, OP Mannan, AUDA ONT Ph speremecees’, Ra rreniiid fas TY ATT ee TTT Pa Hipvrne secchaanutt rete ‘Oar ot wANys Daina at oe Tecpel, ||) (177 | BY fit rouble linia Nit rach Neca inemeivet ti Maa ai, aneknenna a TL A ne | Lal Che r | Rear ron ade r/R” e. ie Ge - os 3 i) De iil AL DOO As Saal TTY PLT TT] tt setae Widalelal aa maaan a ao Arann AA mAAL Ay %: Ww Ms AiiLtT i panera TT Ht oF. Nal ree agA0a rr | 4 badanan yy STE Ming WA, OWA pn any ala! | | tegpo ie 3 Sans ten aa TW reall Lateef. 1 Ee Prem, ‘a Pit é miguel wi arr’ Via Gm: ideqf sary egpreed id if \ wig e jwreat! aypetemeg en. Cees UU yn MHNSE yy, yordu YY anh Ap, Loggers Pelt: 4, “e dh Bed Pe 7 Ani prariertiny ‘prs PrAe- Upper oauull sith ~ saegeeerc tape | i tae hd Bhan: vw Y~, yh, pha eAaahsareMinnahmaacraeeidas .pectae Ny ePhe PE Ws pat Ly AA "5 i -a| PP raed Tey “| ‘w"e" me - iy 4 bt | X Wy : pent” Ln Ar \” pe LL \ ( ’ ; f oe | a= \ i > 4 oo prapea- aA,. an - | tk ere B iad Dn SV) Ee Angie's Poet ¥ AAA / ¥ aft wen, ary sae mp nae sees, ry. poe, yey Y ria ¥ V r»ta- Aion p one ry a: { a my’ XY Onaae {YU € OAT oe? Rear 8. Re 1 TTT v9 a pave Et Ne a | HUKR j ay Oy ae, or Da anions ata PT ea Mueehin TT) AUT ee ) a 2 pS ose me sa a) ren) - z -e ae @ Ap euaaeely Mar Atna “hn Ag ot es “phe ra¢ib ag oacutnitt a@-- ~ ry’ BLA Wel har ine ang Sa on 4 Yu aad Se PY LA we veey & ee: IT AR eo, 71 ORR : Ae. se ag 4a | ; he a we we wi ty Re, bade Da PE en, MEMEO EL . s C ~\§g > a yu LAL Meofdte, ra ; Wate ReeY by Ten ee) Pofie,’ | || | ii, Meryem, naarsat -8~ ‘° & 5 hand Paes y } i ae Ws _eunaaagat rrr TTR TL a EAL | oe “ity, saa li iii it! rv PARRY Wy AAR ay + ges wary TTT TT kt easing AM WAP y ~G +f wat VIG ny saReen ww ents « i i Vw! orre a ey | r. \ aoe i _.aAay Ra. mY a Goud 3 = deat ey a SATS